sister inlaw is secretly bitchy

momma of 4 🙄😂😍😘😟😭

All right so I don't know if this is the right place to post this but I just have to go on a little rant and I need some advice so I've been married to my husband for 7 years and his sister drives me insane at first I wouldn't really say anything . but then she kept telling us what to do with our children so I confronted her about it in she didn't say sorry she was just upset so I forgot about it at this point I literally cannot stand her I don't even like when she's around and every time we go to their parents house they have to have the whole family over there .well she tries to be friends with me .but then in front of everyone if anything comes up that she doesn't agree with she Whispers something snoty and acts like a total biatch but no one cares except for me I like his family just not her . And really this is kind of a long story short because so many times she has made up things about my sisters and I have confronted her she cried and played the victim and never said sorry for it and she also said one time that she wished my best friend that is married would die so she could marry her husband which is freaking horrible considering after that my friend got a horrible disease and almost died she has recovered now and is healthy. so Any advice on what to do to not look like a horrible person. I just don't know if I should try to stick it out and try to be friends or just give up and try to avoid her