YAMDNBU!!! I had this with my MIL, although was spared having to say anything by her Mother, dh’s grandmother giving her an absolute bollocking when she tried to pass full cups of boiling hot tea over my tiny newborn dd who was being held by her DM. She had already tried to drink tea with dd in her arms and her Mother had taken baby off her, whilst tutting loudly, saving me the job of saying anything!
So when she held a roasting hot cup of tea over my baby, her Mother screeched
‘For goodness sake X, have you no bloody common sense! That’s twice you could have scolded baby! I am so sorry Caledonian, X hasn’t had much experience with babies in a long time and as a result she has no common sense! X look at Caledonian, her tea was cold before she drank it for a reason, it is bloody stupid/ no dangerous, to hold a baby and drink boiling hot tea at the same time!’
GMIL is a matriarch in that family and my dh is not very fond of her as her cutting remarks can border on cruel. MIL is just like her, they are both narcissists, however MIL is very much scapegoated by her DM. I actually felt sorry for MIL at the time, more so, because of her affront, bright red face and then being forced to phone and apologise to me again afterwards (her M was staying with her). However I was also grateful that GMIL had brought it up, as I had already spoken about it with DH and he was going to say something that day- which would have 100% have been blamed on me!
Thankfully, MIL was reluctant to make the same mistake again. Often asking me to take dd when she wanted tea! In fairness to GMIL, she was right, my MIL has zero common sense, my dh was lucky to survive childhood, especially when she left toddler dh unsupervised next to a 30ft ladder, which was up against their house as fil was cleaning their gutters. FIL was getting something from their garage and came back and got the fright of his life, finding two year old dh at the top of the ladder! He shouted up to dh to hold on tight and carefully climbed up, as fil reached around half way though, dh panicked and lost his footing, he hit his head on every step, but fil caught him and thank goodness he survived. He does have a misshaped head though.
I spent my children’s toddlerhood coming up with excuses as to why I didn’t want my children to stay with mil on their own. I volunteered to stay with them, or have dh stay with them but that was not the same apparently. My dh thought it was because of the long history between us (we went nc several years after that, due to inlaws toxic behaviour and intense hatred for me) but it was more because my mil honestly lacks common sense!
If you want to avoid confrontation, could you purchase say four insulated mugs with safety tops- contigo/ apex are my favourite as the mug is locked in between sips. Then you can make up tea in the mugs and say your HV had told you a story about a new baby in her area being scolded with hot tea and had recommended that anyone holding the baby to not drink hot beverages and when around a baby/ toddler to only used insulated non spill mugs. Either that or have say your dh or dm to intervene and ask her not to do it. It doesn’t need to be as gung ho as my GMIL was- I still feel for MIL as I still feel shame if my own Mother tells me off now!