I'm never usually a fan of female characters in games - they irritate me to the point of not wanting to play. I cannot stand the three standard types you seem to get: ball-breakers who are basically male characters re-skinned, ridiculously over-sexualised fan-service type women and dozy, helpless creatures who just whine and cry all the time. Mercifully, Kat (to me, at least) seems to be normal. Aside from the whole psychic thing she's got going on, she seems like a normal, regualr, cut me and I bleed type of person who is actually pretty likeable as a character and doesn't try to be someone she isn't.
I especially liked it during the *S.W.A.T cutscene when she says she's scared and wants to know what they'll do to her*- it was just acted out pretty perfectly and I respected her character more for it.