I took the step back with my MIL (when I was still speaking to her) and it became part of the problem she had with me.
She used to complain to DH that I (and her other DIL) were not making her feel welcome enough in our homes.
She would be offended if I didn't speak to her on the phone when she rang to speak to DH, but often he would chat to her for two minutes and I was on the phone for a good hour. If we visited them or they came to us, DH could carry on as normal and completely ignore them if he felt like it, to watch TV or read the paper or even go out, but I had to be right there on hand to provide entertainment the entire time.
It was very much, as you say OP, that this was somehow woman's work even though she is DH's mother.
And yet at the same time, if she felt that I had slighted her in some way, usually just by being busy when she rang or not stopping everything to accommodate her, it suddenly became very much DH's problem to speak to me and put me in my place (she said that once, those exact words).
Leaving DH to have a relationship with them was somehow twisted into stopping them from having a relationship with them.
I wish you luck sorting it out because it can be a bloody minefield.