When I used a menstrual cup, I bought a pot for the sole purpose of sterilizing it. Menstrual blood is not dirty but then again, it's really intimate and it's really understandable that other people might not want to drink from the coffee pot after that
Yeah, it is good of her to at least sterilize it, but her implementation definitely needs work. Sterile or not, I wouldn't use it again. You should let her have the shared coffee maker, and get your own after this. Or get a new roomie.