Name: mystery woman
Other Names: unnamed woman; woman; unnamed mystery woman; the mystery lady
First Appearance: Marvel Knights Spider-Man #13 (June 2005): "Wild Blue Yonder, Part One"
Number of Appearances: 6
Teams/Affiliations: The Hand
Ally: Absorbing Man
Worked for: The Owl
Note: trained by the Hand
A "mystery woman" whose name was never revealed partnered with the Absorbing Man. The two were working for the Owl as assassins, killing everybody on a list he provided to them.
The mystery woman was an extremely proficient and effective assassin. But she wearied of what she regarded as "unprofessional" behavior and general stupidity on the part of her partner, the Absorbing Man.
The mystery woman ultimately betrayed the Absorbing Man, tricking him into turn into a powdery narcotic (cocaine, or something similar). The Owl's people then divided up the Absorbing Man drug among drug dealers, who sold it at a premium price throughout New York City.
The magically empowered Absorbing Man was able to reconstitute himself. He came after the mystery woman and the Owl at the Owl's headquarters. He killed the mystery woman by delivering a crushing blow to her head. The Owl managed to escape.
During the course of these events, the mystery woman learned of Spider-Man's secret identity (when he dropped his wallet, which she picked up). So Spider-Man felt a bit relieved when she died, which he instantly realized was a selfish and unworthy thought on his part.
Suggested links for further research about this character and the character's religious affiliation: