In 1891, after surviving a series of miscarriages, Amanda Mueller was accused of being the Black Womb killer.
Major Story Arcs
The Great Mother
Her obstetrician was none other than Dr. Milbury, an identity used by Mr Sinister. Mueller was married to Daniel Summers the great-great grandfather of Cyclops, Havok and Vulcan which makes her their great-great grandmother. Daniel would leave Amanda with there only son because he couldn't handle the accusations.
The Black Womb Project
Around World War Two she was part of government research project that was gaining research on mutants. Other members were Kurt Marko (father of the Juggernaut and stepfather of Charles Xavier) and Irene Adler (lover of Mystique). Amanda must have had a slowed aging factor as she gave birth to a woman called Fontanelle who is now approximately in her early fifties. Amanda headed the Black Womb Project in her later years. In one video she was shown to smother a mutant child for her research.
Recently, in X-Men: Legacy, Amanda attempted to gain Mister Sinister's powers by putting a code in her DNA that would cause her to partially transform into Sinister once a machine called the Cronus Device was activated. Fortunately, Gambit and Sebastian Shaw were able to destroy the machine before it was activated.
Black Womb is supposedly immortal, though not immune to the effects of aging.