Wu Mei-Xing was once a theoretical physicist doing research on the Higgs Boson, a theoretical particle that would help determine the origin of mass in the universe. One day while working near the particle accelerator there was a containment breach and she was exposed to the particles inside. This caused her to be unable to birth children and because of this her husband left her.
At first she simply focused on work but the reality of no man wanting a barren woman soon took it's toll. She turned to alcohol and often wished for death. Three days after an encounter with stranger she found herself as pregnant as a normal woman would be at the end of her cycle and went into labor. She gave birth to twenty five children even though there was no way they should have fit inside her.
The children grew rapidly and by the next day they were about ten years old. The following day they had aged further and gained metahuman abilities. But by the eight day, they were all dead. Director Jiang saw the value in her and her miraculous children and portrayed her as the mother of Chinese heroes. She was happy to do what was necessary for China and would breed with army volunteers or other members of the Great Ten.
Powers and Abilities
Just as her name implies, she gives birth to a constant stream of super-strong progeny, in litters of twenty-five every three days. She has thousands of these children, even though they are short-lived; the record is twenty-five years. She uses a special walker to get around when she's near-term.
The Mother of Champions also has stated she need not eat or breath to survive and has no problems surviving deadly radiation.