R.A.
I would not beat around the bush with her. I would just tell her that this is between you and your husband. (Especially if you don't want to discuss it.) My MIL is the same way. I just have to tell her strait. She usually gets mad, but gets over it. I also have to communicate with my husband when she says things to me b/c she goes to him and asks him the same questions trying to divide us in our decisions. Good luck