Might Lucille Harewood have been a descendant of Khan? If it's true, that fact would not be necessary to explain why he chose her father out of all the other possible employees who might blow up the Kelvin Archive; Thomas conveniently worked there and had a weakness, a dying daughter he would do anything to save, and Khan exploited that. But it would add an interesting additional what's in it for Khan layer - his line (perhaps through her mother's side) continuing.