Need some advice!

Me and my boyfriend have been together almost 4 years now, and are expecting our first child together on October 20th.. me and his family have most definitely had our ups and downs, but lately we’ve been pretty good. His god mom (his moms best friend) however has it out for me. She holds things I’ve done in the past against me and treats me like I’m a terrible person. I’m only 21 I’ve made mistakes, but I’ve changed and I’ve grown from them, and I think I’ve done a lot to prove that. Yesterday was my boyfriends brothers gender reveal party.. his girlfriend is pregnant also. They went to the back yard and shot a balloon full of confetti. Me being 38 weeks pregnant with 2 herniated discs in my back needed to sit down for a minute so we walked back to the front. I got some food, sat down, and we walked back to show that we were supporting them. My bf’s god mom proceeded to tell his brother and mom that I had an attitude, made rude comments about the fact that they were having a girl, and did a rude hand gesture. Mind you I didn’t do any of this. My face is the face of a person carrying a 7 pound person on a rather small frame. I’m in pain, I’m tired. But of course his family believes everything she says and I get made out to be a terrible person yet again. My question is should I allow someone to be in my daughters life who deliberately disrespects me and tries to ruin my relationship just because she’s been in the fathers life since he was born? I’ve tried so hard to like her and be polite to her but something like this always happens. Personally with the way she’s treated me for the last 3 years I don’t think she deserves to be in my child’s life, but I’m trying to give the benefit of the doubt. Any advice helps.