Yup. This.
Last summer, after 6 years of her increasingly controlling and utterly unhinged behaviour, I literally wrote to her: "you are not the matriarch of mine and (husband's) family. I am. You are not (children's) mother. I am. Please, I am begging you, please respect me as (husband's) wife, (children's) mother, the wife of our home and as a fellow capable adult woman".
The above was in response to her sending me dictatorial and manipulative texts about, amongst other things, me supposedly keeping the children away from her (it was a Sunday, she'd seem them the previous Weds and Thurs) and demanding that I stop letting mine and my husband's friends come over, and stop going to visit them, because she was "unhappy with people outside of the family being around my grandchildren".
This was all a few days after she'd literally gate-kept my husband's health status from me after he'd gone to hospital with a then-not-confirmed heart attack. He'd called her to ask her to watch the kids to let me go to him and she'd instead gone to him, put the phone down on me rather than put me onto a doctor or nurse when, after an hour of waiting, I called him to ask how he was (he was being assessed, so she had his phone), put herself down as his emergency contact with the ward staff, then took more than an hour (when it's 15 mins away by foot/regular bus or 5 by taxi) to get to ours to watch the kids while I went to him - she wasn't upset, worried or panicky by then, she was calm, nonplussed as to why I was upset and almost hyperventilating (since I thought she'd been called back to hospital, and my husband was dying or dead), and felt the situation was fixed because she'd dealt with it. She had actually gone home first to pick up some mineral water (I kid you not) before coming to ours.
Rather than listen, take my heartfelt plea seriously, even consider anyone but herself, on the Monday she instead went to visit my husband and spent the entire hour (I was up next; he could only have visitors during a 2 hour period) ranting and railing about me. My husband had had had a double bypass 3 days earlier.
.