That sucks, to be completely honest. I just explained my habit to my mother and she seemed to understand. However, 1) I didn't live in her house at the time and 2) She had the common misconceptions about it and I made sure I debunked those for her.
Also with some of the comments already posted, DO NOT get a KM if your mother is going to get grabby and get rid of it. 100+ dollars just going in the trash if she finds it.