Moon girl was published by Max Gaines, who had been the first publisher of Wonder Woman. By 1947, apparently regretting that he had let the amazing amazon go to National Comics, he felt the need to once more produce a myth-inspired superheroine. "The princess of the moon," as she was called, was not from the moon at all but from Tamerlane's legendary capital, Samarkand.
It's a magic moonstone, worn on a choker, that gives Moon Girl "the strength of ten ordinary men and guards her against all harm." Even without her moonstone, she was a superior creature. According to her very romantic origin story, the princess lived in what appeared to be a matriarchy; no men were evident. Her romantic interest was Prince Mengu. The prince thinks, "What a woman! I came a thousand miles to find her, and she shall be my wife!" It was never specified, but the prince was probably Greek. Later in the story, he tells Moon Girl, "I am of the blood of Hercules."
Moon Girl was not as eager for marriage as the prince. The queen, her mother, tells her "It is decreed that the man who takes you for his wife must first prove his superior strength!" and she gives her daughter the moonstone. "Once you wear the moonstone, no man will be your master!" she declares.
The contest between Moon Girl and the prince which followed borrows a little from Wonder Woman and a little from the Greek legend of Atalanta. However, Moon Girl, with the magic moonstone around her neck, proved to be invincible and the prince loses the contest.
Moon Girl finds her way to America and takes the pseudonym of Clare Lune to dedicate herself to "the task of creating a better world." She also has a moonship, an aircraft which she controls telepathically.