Addiction is a family disease, affecting all who love the addict. Not everyone is in recovery or at the same place in their recovery and we each have to find our own way.
Remember that your MIL is sick too, say a prayer for her, and then trust your instincts, trust your own recovery and the heck with what anyone else thinks or says.
To thine own self be true, that's what recovery is all about. Just do what is right for you and know that you don't have to talk to anyone you choose not to.
Hugs