My sister has got the nail biting habit and trying to get rid of that but unable to do so. Could somebody suggest tips to get rid of the biting habit.

Does she wear nail polish? Ask her to tie a bright coloured thread around her wrist or her finger. When she sees the thread it might deter her from doing it. Ask her to stick pictures of beautifully painted nails on a place she sees often namely, fridge door, bathroom mirror etc. Hope this helps.

Hehe may be she should chew some gums so she could divert her biting attention to the gum instead of the nail.

I've realized that my nail-biting habit is tied to a certain behaviour of mine. I bite my nails when I'm deep in thought or if I'm trying to figure something out. Have your sister try to pin point the reason for biting her nails, and maybe it'll be easier to put an end to. (I still bite my nails, by the way.)

Behavioral treatments are based in discouraging the habit and replace it with a more constructive habit. The most common treatment, as it is cheap and widely available, is a special clear nail polish that has to be applied to the nails.

Self-control is the best way to protect your nails from nail biting. Nail biting habit will create a negative personality towards others so try to control by yourself otherwise consult a doctor to control it.