Ravenmum - really?!? If I was in someone ELSE'S house, sat on my arse on a chair, and the hostess starts to sit on the floor - especially after having a c-section - I would be off the chair so fast you'd think my arse was on fire.
How is a woman recovering from a c section meant to carry a chair in from another room anyway??
Mermaid - Different people have different approaches to these things. The only "wrong" way, is to say nothing at all, and let it turn you slowly insane.
When you start getting a little more sleep, I really think you could do with reading up on assertiveness, and trying to put your foot down more. Whilst, yes, this is your husband's family, he has already shown that he is too much of a coward to say anything about it. Husband or no, you should be able to rely on yourself if you need to.
If someone makes a barbed comment, call them out on it, either directly or dripping with sarcasm.
"I know X who moved to that area and everyone was so posh and unfriendly that he came home within a year"
"Well of course. People in our area normally have their mouths so stuffed with caviar and macrons that it's difficult to make small talk" OR
"Maybe he just missed getting regular exercise from having to run away from the street thugs/muggers around here" (sweet smile)
"How are you doing?"
"Okay, but infected"
"Well you look fine to me"
"Thank you. That would be the maybelline." OR
"Thanks for your input - remind me, where did you do your medical degree again?" OR
"If you need "evidence" then I can show you the bruised, pus dripping wound if you like? No? Oh okay then".
More than anything, you need to put yourself first.
If someone asks for sugar, tell them they know where the cupboard is.