Monster in law?

i need to vent and get an am i over reacting reality check.

my mother in law or should i say monster in law is the biggest pain in the bum that i have ever met, and yet to my OH im just malicious towards her.

when we announced i was pregnant she was LESS than enthused about the whole situation and if anything made me feel absolutely guilty for being pregnant, my partner and I were so excited.. after 4 miscarriages between us from previous relationships finding out we were having a baby was amazing news.. all through the pregnancy she didn't want to know we barely heard from her and maybe saw her once in the whole 9 months she bought us a second hand chair that was covered in stains and made us feel bad when we noted to her that it was covered in stains, would not have taken her two minutes to pop it in the wash & we would have been none the wiser but a polite comment turned into oh you're a b*tch for making her feel bad.

once our daughter was born she suddenly wanted to be all involved making requests to come up any time and requesting to be called stupid names - now i understand she was obviously excited about becoming a grandmother again (we have two nephews)  but it feels like a little too late... but now when she does come up its always on route to do something else she never makes a whole day for my daughter or her son and it makes me really sad. she is always saying stuff like oh your daughter is chubby, fat and that her son is fat and he just takes it as oh shes joking (it makes me sad that he thinks this behavior is funny &acceptable)

shes now guilt tripping us if we say that she cant come up because we have plans saying she feels like shes being pushed out - basically expecting that we drop everything for her.

I'm at an absolute loose end with what to do. if i say she cant come up because we have plans im called malicious. shes constantly making me feel guilty because my parents buy my daughter stuff, ("oh i wish i could buy her nice things" - whilst being out on the piss every single week).

Help please.

Mumlifemaddness x