She won't accept any of this and starts giving me a lecture about how undergoing chemotherapy was the WORST thing she ever encountered, because DRUGS R BAD!!!!1. I retorted that chemotherapy was the BEST THING she ever encountered because it SAVED HER LIFE.

I'm sorry to say this OP, but fuck you. I've been on a cocktail of drugs for over a year now for severe Tourette's (nothing even close to chemo), and it fucks with you more than I could ever explain in 10k characters. Your mom sounds seriously traumatized from her experience, and it isn't helping anything to have her grown daughter treating her like a moron after the fact.

Homeopathy and bullshit science prey on the vulnerable and desperate. I've seen so many brilliant friends and family members get sucked into the marketing of pseudoscientific "cures," not because they are dumb, but because they were desperate. I hate homeopathy with a fiery passion, but I'll admit in the past I've looked into certain things like essential oils and chiropracty to help me.

My advice to you would be to first apologize to your mother for rebutting her so aggressively. It would clear the air if you admitted you were wrong in attacking her beliefs, even if what you're saying isn't wrong. Secondly, suck it up and listen. It sounds like your mom is healthy now, unless she has a major health scare and refuses to help herself, let it be. It's her life, she's an adult, let her make her decisions for herself. If she wants to spend a few minutes talking about something that's important to her, let her. You don't have to gush about how great it is, but just let her talk. Change the subject, and forget about it.