Rant sorry

Sorry for the rant but I'm about to snap.

My brothers have a different father than me an I've always been close to him because he's been in my life since I was 2. He remarried and now has 2 kids with his current wife. She is so annoying like I can't stand it. Everything has to be about her. She is absolutely nothing to me but I love her kids as if they were my own brother n sister because they are my brothers siblings. Since I got pregnant she will make comments "well what will the baby call me?" She goes around telling people that she is the mother of 5! Claiming me an my 2 brothers as her own. She never even raised my brothers! Then tries to claim my kid as her grand child. Well tonight she goes an comments on my status "I hope you have him on Andrews birthday so he will be his birthday present" like wtf?! Why does anything that involves me or MY CHILD have to do anything with her? I want my son to have his own birthday an not be associated as a freaking object. He is my child, not someone's birthday present. She's thrown a fit because I said I only wanted my mom, brothers, their dad and my husband immediate family at the hospital when I have my son. She said her an her kids will be there because they have a right to be there. Here I thought it's my choice on who comes to the hospital but apparently that isn't the case. Literally anything I want I have to keep to myself or I end up offending someone. I'm about to go off on her but if I do then I lose my brothers father. He is the only father figure I have because my own dad stopped talking to me. I don't feel like I am over reacting. Like this is my pregnancy, my baby, my delivery but she treats it like it's all about her. Her kids are 7&8 one being autistic an she doesn't see why I don't feel comfortable with them being at the hospital. I just think they are too young an it's gonna cause stress on me. I love both of them but I just think it'd be too soon an too much on me. What if she tries to take my child out of my hands? What if she tries to let the kids hold him and they drop him? Like no I just can't handle that kind of worrying just moments after having him. I'm sorry for how long this rant is I'm just freaking out.