It's been done before. Group of women who are genetically engineered to be better than most, secret project with dead mothers, one escapes with her child and goes into hiding. Girl grows up, finds she's different, is found by others of her group.
It's not a bad example of this genre, quite readable, and at first the policeman is quite hostile to Faith and he behaves in a way that makes him very believable. I'm not sure the sudden conversion from dislike to love is as believable but is part of the Romance novel convention.
The killer is also interesting and quite well fleshed out. A little more fleshing out and this book would work as a pretty mainstream thriller. In fact it's better, in my eyes, than many of the thrillers going around.