31 weeks, not speaking to my alcoholic mother.. need advice

Lauren • Baby boy April 2019😍

My mom took up drinking again recently, more than just a relapse after years of off and on sobriety. She doesn’t know that I know about every single one her other relapses, just the ones she’s decided to share with me. Due to my being 31 weeks pregnant I’ve decided not to speak to her until she gets sober again. My sister has told her this and she said she doesn’t understand why I’m being so harsh on her (basically). I told her the last time she relapsed and was forced to tell me, that I don’t want my son around that because she’s not the same person when she drinks. My sister reminded her of this, and said if she doesn’t stop she won’t be invited to the baby shower or birth. Of course her response was that I need to be understanding of her and she’s going to wait for me to call her. I recently got into a car accident and didn’t call her because I was afraid she would make it all about her, my sister told her about that as well and she made it about her again “I can’t believe she didn’t call me, I’ll just wait for her to call me, I need her to be supportive right now, blah blah blah”

This is the same woman who used to come home drunk from work with my dad and get into a fight with him every night til she would beat on him, all while I tried to keep my brother and sister from hearing and keep her from hurting my dad to bad. The same woman who had an affair with her my my dads best friend, and then let me believe he raped her when I heard them in the next room, leading me to believe it was my fault for not running in there and breaking it up (WHEN SHE WAS HAVING AN AFFAIR THE WHOLE TIME!). The same woman who through such a fit about our house not being clean on my graduation day that she said she wasn’t coming to the ceremony, literally up until 15 minutes before leaving for it. Who got mad at me and my fiancé for picking her up from her boyfriends when he called the cops on her and stopped her from getting arrested. Who was drunk when we showed up after driving 4 hours to see her, then got mad when we called the cops and left the same night because her boyfriend pulled out a knife after a fight. Who threw up on my nieces birth certificate ruining her little ink footprints. This woman ruins everything, and after all these years, since I was 16 (now turning 29) I’m supposed to be supportive of her?

Being a mother has always been my dream. I just need to hear if I’m being irrational, if I should really be putting in more of an effort, or if I should stand my ground, because I feel like I’ve done my part and at this point in my life she really should put in more of an effort to be here for me. She knows more than anyone what this pregnancy means for me. I’m I being selfish? Or is she?