When I refer to my MIL to friends or random people, I say "Mrs. Smith". When I have to address her directly, I usually say "Mom", but that's because for all the years hubby and I were dating, she never told me to call her anything other than "Mrs. Smith". Once we were married, it felt strange by using such a formal name, so I simply reverted to "Mom". It felt less strange than calling her by her first name, even though that is what I would have preferred.
well since I can't call her what I really want to call her (evil grin) I call her by her first name, she's cool with that. I'd never call her mom since she,-thank God- isn't mine, phew! Thank God for small favors. LOL
I Apolgize for the photo !
Evil or not ..... Your mother-in-law is just that...'mother-in-law'... .(Not your 'Mother,' Mom, 'Ma') I believe that name is special to 'the one' you called that since your birth. When your 'Mom' is gone there will be no other who can replace her, so why start now. I think you can come up with some other respectful name you can use.