Where did she get the term Mom-Mom? Is it something that Josh's family has been using, or is it something she picked up from hearing you talk about your Mom-Mom?

I, too, have never heard that term before. My instict tells me to let her be called that (if it was already in their family) because she might be as influential to lil' Nug as your Mom-Mom was to you. If she got it from you, I'd suggest explaining to her why you aren't comfortable with calling her that.

Does that help? I swear, Libras (I'm a true Libra) can never make up our minds.