Completely agree! I’m furious reading how OP has been treated!
Never ever forget: this is YOUR HOME, not their workplace. They have absolutely no right to reprimand you for a member of your household being in their house!!!
If your MIL was walking into their meeting rooms on their office space, okay. However, your MIL clearly has care needs and you’re her carer. As your employer they should be offering you support. Absolutely livid for OP!
We have 2 managers (weird split team set up) and the first thing one of them said was never to apologise for not being on camera or if your children, family members, pets etc “interrupt” I apologised once for my cats jumping into frame and he stopped me mid sentence to highlight this is MY house and not my employers work space. He feels quite passionately about this. Which is amazing to have a boss like that. OP take this further, do not let it lie. Remember, if your company really can’t take you being interrupted they could offer you flexible hours, part or full furlough, changes to meeting times that work around your care duties etc.
This behaviour is sexism alive and well. Women hold most care responsibilities for vulnerable family members, women are expected to “do the childcare” and homeschooling when kids are off. I appreciate there will be examples of Dads being amazing. However, make no mistake, women still carry this burden and employers disciplining women this way is another form of sexist behaviour. Led by policy that benefits men. Again.
I am away to burn my bra