This might be a bit of an essay....
My mother in law treats my partner like he's a baby, and still calls him "my baby"
Told me to pull my finger out when i was unable to do any housework due to hyperemesis,(couldnt even keep sips of water down) losing 3 stone in weight and having to be hospitalised on a drip as her son shouldn't have to do the housework.
Favours her daughters children massively over mine and didn't even get my own children (from a previous relationship) a selection box at xmas but said we had to get his sisters kids presents or they will be so upset (this one caused a huge argument with my partner as he defended her, then said she had bought them something well I'm still waiting to see that)
Constantly said the area i live in is disgusting/rough calls it the bronx, well one day i snapped and said how rude it was and she turned the waterworks on and my partner didn't speak to me for days as i was "out of order"
When she is nice it is so insincere, but my partner doesn't see any of it thinks shes the best thing since sliced bread, the good thing is when she comes round it's literally for an hour and then she's gone