My mother won't quit biting.........?

my mother won't quit chomping on ice. it is so.. annoying. she is 50 and i am 30 and i am afraid the pretty teeth that she has are going to get ruined by the large pieces. she broke one off not too long ago and to get it fixed is like lots of money. she told me it is like a really bad addiction, and she can't quit. i feel so sorry for her because i wouldn't know how it feels to be like that. if anyone has any suggestions please let me know. thank you in advance.