Kala, the daughter of Jor-El of Krypton, arrives on Earth as an infant early in 1923, her spacecraft crashing on a farm in Bavaria. The farmer and his wife, so far childless, bring her home and rear her as their own.
It isn't long before the couple discover their adopted daughter is special. She's never sick, she never gets hurt. And as she gets older, she becomes even more special, with abilities beyond those of mortal men.
The National Socialists come to power in Germany in 1933. The Kants, the loyal Germans they are, join the party, and Klara joins the Jungmädel branch of the Bund Deutscher Mädel (the female branch of the Hitler Jugend). Her abilities soon bring her to the attention of the local SS chief. He grasps the possibilities the blue-eyed, golden-haired ultimate example of the Master Race presents, not only for the Reich but for him personally.
Of course, she's actually too young to be a member of either the armed forces or the SS. But given her special abilities, she's much too valuable to be ignored. As those abilities are explored further, it soon becomes apparent she's even more special than anyone had originally believed. Or even imagined.
The preteen girl can run faster than anybody else. Faster than a man riding a bicycle. Faster than a car. Faster than a motorcycle.
Yes, she's faster than a speeding bullet.
She's not just stronger than a grown man, she's stronger than ten men combined. Her muscles are more powerful than those of a hundred men combined. More powerful than a thousand men combined.
Yes, she's more powerful than a locomotive.
She can leap far and high. All the way across a football field. Lengthwise. She can leap over a pole-vault bar. She can leap over her parents' farmhouse. She can leap over the church steeple.
Yes, she can leap a tall building in a single bound.
It's not just that she doesn't skin her knees when she falls. That becomes readily apparent the first time they try to get a blood sample, as no hypodermic needle can pierce her skin. Neither can knives or scalpels. Nor saws and axes. With typical Teutonic thoroughness, they decide to try shooting her. Wanting to catch her off guard, they have a trooper shoot her in the back of the leg. Hearing the gun and feeling a light tap against her leg, she whirls around, sees the bullet smear on her leg and the smoke curling up from the barrel of the man's Luger. Thinking that the man had tried to kill her, she kills him with a single punch. After she calms down, they inform her that it was just a test, which she passed with flying colors. And they agree to ask her permission before conducting any further such tests. Though they probably don't go much beyond hand grenades.
Too bad those special abilities hadn't been fully explored before the 1936 Olympic Games in Berlin. She could easily have stolen the limelight from the American Negro Jesse Owens, amply demonstrating the superiority of the Aryan race.
A special unit of the Waffen-SS is formed to take her under their wing and start training her as a super-soldier. Of course she doesn't need much in the way of weapons training; her bare hands are more than adequate. Though it does get a little difficult to find additional hand-to-hand combat instructors and sparring partners after some of the earlier ones are seriously maimed or even killed in sparring sessions.
It starts out as a nickname, but she soon becomes known, at least within certain circles of the Waffen-SS, as Das Übermädchen.
In 1937, despite her youth, she accompanies the Condor Legion to Spain. There she is blooded (figuratively, not literally), fighting alongside the German-backed Nationalists against the Soviet-backed Republicans. Not openly, but she's great at little raids, wiping out isolated Republican outposts or taking out a particularly well-sited machinegun nest.
After Joe Louis KOs Max Schmeling in June 1938, there is some talk of training and then putting up Übermädchen as a challenger. The defeat --- nay, the total humiliation and eventual destruction --- of the American Negro heavyweight boxing champion of the world by a "mere" fifteen-year-old blue-eyed blond girl would amply demonstrate the superiority of the Aryan race and serve to at least partially erase the humiliation caused by that other American Negro at the 1936 Olympic Games.
September 1939. She's there in Poland, though they continue to keep her in reserve as their "secret weapon." As it turns out they don't need much of her help to overrun half the country in less than four weeks. (The Soviets take the other half.)
April 1940. The Germans overrun first Denmark and then Norway. Since officially she's still being kept in reserve, she has quite a bit of time for R&R. This gives her the opportunity to explore some more of her physical abilities, the kind of abilities that weren't explored by Herr Burgermeister Luther. Unfortunately for them, some of the men "assisting" her in her explorations are injured when she presses their hands against her breasts or even killed when she traps their heads between her legs. Or a severe case of exposure or even drowning should she happen to drag a man into a near-freezing fjord.
While in Norway she discovers another of her physical abilities, that of flight. That comes in handy in the rugged terrain, flying across the fjords and over the mountains in order to seek out the opposition. Despite being held in reserve, she does see some more combat. At least she kills more of the enemy than she does of her own people. And she is getting better at both; killing people on the other side and not killing those on her side.
May 1940. The Germans invade the Low Countries and France. She takes more of an active hand, single-handedly reducing some Belgian and French fortifications. When the British Expeditionary Force is trapped at Dunkirk, she uses her new flight powers to knock down the Royal Air Force fighters trying to cover the evacuation. As a result, the rescue flotilla is forced to withdraw and the bulk of the BEF has to surrender.
The French campaign shows the German High Command that the Western powers, especially Great Britain, are a tougher nut to crack than Poland and Norway, and they unveil their "secret weapon." Thus, when the Luftwaffe battle the Royal Air Force for command of the air so that the Army can cross the Channel, Übermädchen takes a very active hand, wearing an invulnerable uniform made from the swaddling clothes her parents had recovered from the remains of her crashed spacecraft.
Since she's not officially a member of the Waffen-SS, she doesn't sport the double runes normally used by that organization. Instead, her uniform sports a single golden lightning bolt slashing across her generous chest.
Hurricanes and Spitfires fall (literally) before the flying seventeen-year-old Übermädchen, leaving the way open for the bombers and strafing fighters. Unlike the short-range fighters, she can roam the length and breadth of the British Isles. Nor does the dark of night affect her. And day or night, her bright blue eyes are as good as any radar system.
With the RAF out of action and most of the army having surrendered on the Continent, the Germans cross the Channel. The Royal Navy refuses to commit their heavier units without air cover, and the lighter units are blown out of the water by the combined efforts of the Luftwaffe and Übermädchen. The Royal Family and much of the government evacuate to Canada to continue the fight from there, continuing to reinforce their forces in India and the Middle East.
Übermädchen and some personal "aides" spend Christmas in Buckingham Palace.
Over the winter Italy invades Egypt from Libya and is beaten back, losing Tobruk. They ask Germany for help, and in March 1941 Germany sends Rommel and the newly formed Afrika Korps. And someone else, who proceeds to spearhead the drive to the Suez, brushing aside a last-ditch British defense at El Alamein.
In May 1941 the new battleship Bismarck is dispatched to prey on the British convoys carrying troops and supplies from Canada to India. When the pride of the Kriegsmarine encounters some difficulties in the Atlantic, Übermädchen takes time off from the Africa campaign. With the eighteen-year-old girl running interference, the damaged battleship makes it safely back to Europe, leaving behind a number of sunken British warships in her wake.
With no opponents left in Western Europe (or North Africa, for that matter), the Reich can now devote its full attention to the originally-intended foe. In June of 1941 the Reich invades the Soviet Union. The invasion was originally planned for May, but the schedule was pushed back a month to give her time to wrap things up in Africa. The eighteen-year-old Übermädchen spearheads the drive to Moscow as winter falls, but the Soviet government withdraws to the east, continuing to fight.
With Britain apparently out of the war, the Japanese decide to go on the offensive in the Pacific. In December of 1941 they attack the US Pacific fleet at Pearl Harbor. Hong Kong, Singapore, French Indochina, Malaysia, Indonesia, and the Philippines quickly fall.
When a Soviet offensive threatens the Sixth Army at Stalingrad, she leads the counterattack, and it is the Soviets who get cut off and suffer a great defeat there. Still, the Soviets continue to fight.
The Soviets launch another massive counterattack at Kursk. But all that massed armor merely give Übermädchen even more opportunities to demonstrate her superiority.
As powerful as she is, not even Übermädchen can be in more than one place at any given time. She is still too heavily involved in the Soviet Union (it's a big country), with occasional skirmishes in the Middle East, to help out in the Pacific. Since North America is safe from German attack for the time being, the Kriegsmarine unable to project adequate power over that great a distance, even with Übermädchen's support, Roosevelt steadfastly refuses to commit US forces against Germany. Churchill has little choice but to join the Americans and concentrate British efforts in the Pacific.
Leaving not much more than a screening force in the Atlantic, the Anglo-American alliance stop the Japanese advance in the Pacific at Midway and proceed to roll back the earlier Japanese conquests. After a bloody battle for the Philippines and an even bloodier battle for Okinawa, the Allies prepare for an invasion of Kyushu, the southernmost of the Japanese home islands.
Knowing that the Japanese defense of the home islands will be furious, the Americans have been preparing a secret weapon of their own. But something goes horribly wrong in Alamogordo, wiping out the entire town. Weeks later New York City is destroyed by an atomic bomb, delivered across the Atlantic by Übermädchen. Three days later Toronto is likewise destroyed. Faced with the threat of further atomic attacks, both the US and the British Commonwealth are forced to surrender unconditionally. The Latin American nations quickly follow suit.
The Soviets stubbornly continue to fight despite the atomic threat. But with the Western powers out of the war, Übermädchen is now free to concentrate her full attention on the Eastern Front again.
Finally locating the Soviet government in a bunker deep in the Urals, she smashes her way in and kills Stalin when he refuses to surrender. She then proceeds to kill the other bigwigs one by one until the survivors agree to surrender unconditionally.
This leaves Germany in control of the entire planet, except for the vassal states of Italy, Japan, and Spain, and a few neutral countries like Argentina and Switzerland.
Franco's Spain, having stayed out of the war, gains nothing. Italy gains much of North Africa; Algeria and Morocco to go with Libya and Ethiopia. Also western Egypt, though Germany retains the Suez Canal. Japan gains eastern China, Indochina, the Philippines, and most of the Pacific Islands, with Germany claiming Hawaii, Australia, and New Zealand.
Of course, Übermädchen is free to go wherever she wants to go and to do whatever she wants to do. Who's going to deny her anything?
When Hitler's health starts failing, a power struggle ensues in Berlin. Joining one such "discussion," she proposes her own novel solution: "Anyone object to naming me Überführerin?" One man objects, and he's immediately (and terminally) removed from the discussion. There are no further objections, and she's given the title by acclamation.
Not that she bothers with the minutiae of ruling the world. As long as everyone recognizes her as Überführerin, she'll let them go on with their daily lives. She'll just live a pampered life of ease, going from one of her "homes" to another all over the world; Buckingham Palace, the Kremlin, the White House, the old Hawaiian Royal Palace, and others. All of them, of course, adequately provided with a steady supply of sex toys. After all, these sex toys have a distressing tendency to break after only a little use.
Thus, in this alternate reality, the last daughter of Krypton becomes the first Empress of Earth.