Advice? SISTER IN LAW FROM HELL

 Hey ladies.

So my boyfriends family is really INVOLVED in every decision that we make about everything and its just gotten worse since ive became pregnant.

Me and his sister use to be Best friends but we got into a couple fights  (arguments not physcial fights)

But since ive became pregnant shes became very lets say annoying with certain things such as

° what my child does and doesn't need

° telling me my taste is way to high

° making fun of his name

° telling me to change his name or shes not calling him that

° telling me my rules are annoying and im over doing it  and i need to relax

° my bf told his mom the pack and plays price dropped and his sister started arguing with my bf saying that it didn't she just thinks she knows everything

° she doesnt like any of my things i post on fb

° ive sent her things ab the baby ... nothing

° tagged her in things ... nothing

° told people she isnt happy that im pregnant

° told people all me and my bf do is fight .. which is a lie

° said that im not gonna be their for my son and pretty much if me and my bf break up ill give up my rights 

° said that my son is her concern

° said that my son is also HER baby

My boyfriends younger Brother is having a

Baby to 2-3 months after my son which I'm very excited ab cause our babys are gonna be close. Shes more involved in their baby than mine. Which is her call but i feel like since shes acting like this and crap

I shouldn't let her be involved as much just cause she's not putting in Any effort now ya no

She doesnt work all she does is smoke  ( weed )

Mouches off her parents

Shes 24 im 22. She has no kids either btw.

Advice.?