Bit off thread I know. I just think sometimes it's nice to appreciate mils.
No that's not off thread! I love my mil, she's fab! Lots do and lots are!
BUT for the op this is an invasion of privacy and in the context of other stuff it's not ok.
People don't seem to have a very nuanced concept of generosity - doing someone a favour isn't necessarily a nice thing. Some people genuinely don't get that, it's weird.
"I just did your laundry"
"I just cleaned the kitchen"
"I just repaired that lamp"
"I just repainted your house"
"I just had that wall knocked through"
... All those statements would either fill you with total joy or total horror based on your own unique relationships and nothing less
(not suggesting that things escalate like that btw, just thinking of examples).
I hope the op and her mil start to rub along a bit better because that will definitely make life happier for everyone, but it's got to be a mutual thing!