If you truly think your Mom's health would be at risk, or your relationship would be ended, I don't see the urgency here for why you need to confront your Mom?
Why not just throw away the literature just like you do with junk mail or unwanted magazines or flyers or spam email?
Whenever you speak to your Mother, discuss anything besides religion. Redirect the conversation to family life, tv shows, movies, books, politics, world events, news, jokes, games, entertainment, gossip, music, work, exercise, health... Whatever you would talk about with a Non-JW friend.
I see no reason to confront an elderly person and tell them their religion is wrong or tell them to stop sharing things with you.
I would just view it like relatives who give you gifts at the holidays that you don't really like, and will exchange later, but you're still polite and kind to the gift-giver.