it's really tough to say without knowing either of you irl, but it might not have anything to do with you personally. i can't make eye contact with anyone. i've been married for 5 years and i'm only just now able to occasionally make eye contact with my husband and only very briefly.

i guess all i could recommend would be to just flat out ask her if her lack of eye contact with you is something you should take personally. but then i'm a very direct (and fairly socially inept) person.