if she is feeding she has a chance, but with the mouth deformities they can have trouble suckling, making feeding very difficult. vets may be able to operate on her but really they either wont need too (she can feed normally despite the hairlip) or she will not survive long enough to be big enough for them to perform the surgery.
very good luck. i have not experience with hand rearing them myself. the last kitten with a hair-lip we had had an extreme cleft palate and couldn't feed properly so only lived for a few days.
A friend of mine has an adult kitty with a hair-lip so its not impossible that she can survive