Ladies advice please!!

I'm 35 weeks pregnant and baby is coming soon and I'm obviously uncomfortable and having contractions here and there. Anyway my husband and I were separated for couple years and his family didn't like me. Especially his older sister she would brain wash her brother why he shouldn't be with me. And even when we were together she would always talk bad about me in Farsi (they are Persian). She was always really really mean and nasty to me and didn't want her brother being with me at all. Anyways my husband and I have been back together over a year and having another baby soon! Things are really good with his family and I finally! Except this older sister! She is coming into town for couple weeks I haven't seen her and my husband wants me and our daughter to go to his parents house with her there! This is like the last thing I need is to see a lady who hates me and talks crap about me. So I told my husband I'm not going to go over there I don't want to see her. He is saying well done stay home. I still need to go see my sister! What sounds fair here???? I don't want her to brain wash him and I don't want to see her either and feel uncomfortable and have her talk crap in Farsi in front of me! Not once has this lady called to say hi to me !!