S.T.
I was a nail biter as a child and my mom also tried various methods to help me quit - to no avail. I finally was able to break the habit on my own as an adult when I had the will and determination to do it. Now 2 of my three children (ages 5 and 3) also bite their nails. While I am disappointed that they may have picked up on this habit from me, I try to keep it in perspective: As much as I would like them to stop, it may not happen until they have the desire and motivation to stop. In the meantime, it doesn't seem to help to hound or punish them for it, and I don't think it is going to permanently affect their long-term health. I wouldn't necessarily get too uptight about possible "reasons" for or "causes" of the nail-biting since often there are no explanations. Certainly, the poor relationship with her father is a concern, but that is a more serious problem than the nailbiting, imho.