W.C.
She is trying to respect your territory in her own strange way. She taught her daughter how to be a mom. She has groomed her all of her life to love the way that she does, to do things the way that she does, and to have respect for everything that she does. Her daughter has, no doubt called her on several occations and applologized for the things she did as a child that caused MIL pain, and activly seekes her advice and attention. You---don't do any of this. Your husband---doesn't do any of this. for this reason it is easier for grandmoothers to feel comfortable at their daughter's home and not their daughter-in-law's home, because,let's be honest. It is your home and has little to do with your husband at all.
"A man shall leave his mother, and a woman leave her home..."- nothing about a daughter leaving her mother. Just the facts, don't take it personally, but chances are rare that this won't change much in the future. Good luck.