She's right. We use a lot of them in our family -- except for pot, of course. I wouldn't touch it even if it were legal, although I can't say what my stance would be if I had cancer.
My grandma used to make a topical arthritis ointment. Somehow this came up when chatting with my mom over the weekend, and apparently marijuana was one of the ingredients she used. Considering what a straight-arrow my grandma was, I was pretty shocked when my mom told me that.