My DM is fab and I can’t fault her. My MIL is from the very depths of Hell, but lucky for me she’s in the UK and I’m in Ireland.
SIL is Skyping me tonight for a vent. I seriously worry one day SIL will snap and kill her mother.
“You’re far too fat for those jeans dear…what? Well if I don’t tell you who will?”
MIL is considerably overweight herself. SIL is a gorgeous woman, in a Nigella way.
“You drink too much, you eat too much, you spend too much, I don’t like your friends”
Racist remarks regarding my DN’s non-white friends, hating SIL’s own PIL who are just lovely. Ranting about “Foreign nationals” (she’s not actually British).
Today on the phone MIL told me she thinks SIL will be happy when MIL is dead. So she even realises how much she’s pushing SIL to the limits. AND STILL DOES IT!
What’s that about?
In a bizarre twist, she’s devoted to me albeit I’m Irish and she “Hates the bloody Irish” 
She's cut SIL out of her will twice in the last 5 years over perceived slights. DH just tells her to do what she likes, as he'll split everything with his sister anyway.
Instead of being ashamed of herself for forcing him into such a position, she took credit for raising such a "Wonderful, kind man"
That's right, he can't put a foot wrong, no matter what he does or says.