How to stop biting finger nails?

My sister in law, Sasha is 14 now and she still bites her fingernails. I have been trying to help her because she wants to stop. Help anyone? Ideas?How to stop biting finger nails?
Maybe it would help if she started chewing gum constantly. Then there would already be something in her mouth. That, or put a dab of fingernail polish remover on the tips of her fingernails. That'll taste gross when she goes to bite them. Good luck! :)How to stop biting finger nails?
The old fashioned way is tape lol. She could also use fake fingernails. But there is a dog spray for dogs the bite their selves and it tastes horrible yet is edible. It's the worst taste and makes you queasy. After putting that in her mouth she won't ever want to put anything but food in her mouth lol. The flavor i suggest is SOUR APPLE, sounds good but isn't!
I heard that nail polish helps because it tastes bad when bitten off.
鈾ip it in Dog doo doo
They make this ';Biter's Nail Polish';.. You paint it on, its clear.. and it taste bitter. If that doesn't help.. make sure she knows that she can get worms from biting her nails. The dirt under her nails can contain bacteria or even parastic worms.
The way that i stoped biting ma nails was by putting nail Polish remover on my nails and so every time i went down 2 bite it tasted nasty....or every time u wanted 2 bite u nails eat sum nuts(the food) that way u don't even want 2bite u nails any more
tape,sour apple,alcohol








I tried them all





I hear they work but I still bite them


even with crap on them thats really bitter





now I regret ever biting them


=/
wear gloves
I really wish i knew cause i am 14 and i cant stop either
put finger nail remover on the tips of your fingers