what would you do in my situation?

i just wanted to hear everyone else’s opinion and if i’m being dramatic or not. this will be a long post btw....So my sister had her baby July 20th 2018. I was there for her the entire time she was pregnant anytime i could be and had the chance to! When she had her daughter anytime she needed someone to watch her daughter i was always there for her never said no never asked to be paid for it or anything. I loved watching her! Well anyway she used to have a bestfriend that she brung around me and my family for 3 years as my aunt had just passed this girl was there for us brought flowers and eventually she grew very close to me and my family also. well her and my sister got in a fight and my sister won’t talk to her again. honestly the fight was over because the girl had slept with a few guys and my sister was mad about it. very childish. but anyway after they stopped talking we still talked to her because she had been around for so long and what she did behind closed doors wasn’t our business she’s a grown women. My sister was so mad we still talked to her that she wouldn’t let me see my niece and anyone who did talk to her couldn’t see her either. Pretty much using her baby as a pawn. i found out i was pregnant and it really bothered me my sister wouldn’t talk to me, nights i cried and hormones didn’t make it any better lol but anyway the doctor sampled me medicine called Diceglis for my nausea because it was terrible in and out the hospital not eating at all i was throwing up the acids in my stomach so when i tried this medicine it worked miracles for me! i could function as a person lol well anyway my sisters ex bestfriend is pregnant as well and she got the same pills. but my medicaid wouldn’t cover them because of how much they costed so she was looking out for me splitting them with me to where i could function everyday. (my doctor knew about this) so if it wasn’t for her honesty i don’t know if i could’ve carried her this long or if i would’ve ever made it out the hospital. Well anyway this girl has been with me this entire 8 and a half months so far and been a very supportive person for me. Meanwhile because i still talk to her my sister has threatened me by saying “i’m going to beat tf out of you when you pop that ugly baby out” She has told me she hopes i die while giving birth and has even wished death upon my baby. She’s told me how i’m incapable of being a mom and everyone “will be taking care of my baby for me” She has said some evil things to me. And i feel like the argument is between us she shouldn’t have to say such things about my baby she’s innocent. I’ve treated her and her daughter so good and for her to treat me like this all because i hang out with somebody she don’t like i feel is uncalled for. Now that i’m one month away from my due date she is trying to come back into my life. Only if i stop hanging out with this girl tho. I feel like i shouldn’t let her control me and decide who i talk to. I also feel like my baby doesn’t deserve to be around somebody who’s said such harsh things. Majority of my family says “she’s my sister” that everyone says things when there upset. It shouldn’t of ever being taken this far to start with. I know when i see my baby i’m going to see how beautiful she is and it’s only going to make me want to protect her from people like my sister family or not. So i guess my question is if you were me would you try and fix the relationship? Or would you continue to keep the supportive people in your life and focus on the arrival of your new baby? It crushes me that i don’t have a relationship with my sister and maybe i’m being dramatic for holding a “grudge” but i don’t feel like just because she’s family she has the right to talk about my daughter like that and forgiven so easily. and not to mention why would i want to start a relationship with her again by cutting off somebody who’s been good to me and supportive? Sorry this was so long and if you made it this far thank you for your feedback.