Shaw lost her parents when she was younger, and ended up in foster care for most of her teenager life. She had gone to medical school, but was told she didn’t have the right ‘bedside manner’ – so she joined the US Marines.
She was recruited out of the Marines into NSA, from there she ended up working what she would discover ‘relevant numbers’. When they decided to retire her, she was recruited by John Reese.
It took her less than six weeks to figure out there was more going on than two idiots working to help people. When she confronted them about the lack of a heart beat they tried to work their way around it, she pointed out she does have a medical degree.
She didn’t have an interest in being Turned, didn’t see the point. Until a Number went bad, and she lay dying and Joss gave her the opportunity.