wow, turn loose lady!!
I would've just handed the phone over to the husband and let him deal with her...I'm willing to bet you have had other issues with her too, right?
Those MIL's.....I feel for you, I had one from hell for a long time...then she got other DIL's and figured out I wasn't quite as bad as she thought I was
Seems like she would be thankful you gave her two wonderful grandkids and then butt out