His fam is overstepping boundaries already with our unborn baby. How do I handle this?

Bear with me. It’s a long one, but please be patient because YA GIRL NEEDS SOME HELP. Idk what the appropriate way to deal with this is, so I was hoping to get advice from some of you ladies.

Okay, so I’m gonna give a little back story. My and my boyfriend/BD have been together for 1 and 1/2 years. His sister used to be my bestfriend and coworker and that is how I met him.

Anyways, I’m 9 months pregnant. And his sister is waaaaay trying to over-insert herself and cross over boundaries regarding our son. Here are a few examples:

-trying to decide OUR nursery theme for us. She literally went out and bought a bunch of superhero shit to decorate the nursery simply because she thought it was a cute theme. And when I mentioned the first time that we were not doing that theme, she basically shrugged it off and got more stuff. A second time I brought it up she got mad and was like “well me and mom already bought a bunch of superhero stuff for y’all to decorate with”.......

-trying to name him. She was sending me name suggestions literally EVERYDAY. And if we had a name we were considering she always liked a different name better, like her opinion mattered anyways. And then came up with a middle name that she liked and kept trying to push it on us. So I told my s/o I wanted to pick a name and keep it a secret till his birth because I didn’t wanna hear any negativity about it that could potentially end up changing our minds. And when we told her we had a name but it was secret she got mad.

These are just SOME examples of what she does. She literally hounded me every single day at work asking me 100,000,000 questions about have y’all done this, have y’all done that. When are y’all gonna do this this and this. (Things regarding the baby). I can’t even begin to go into that but it was driving me so crazy that I quit my job because I couldn’t handle going to work everyday because of her. It was causing animosity and she eventually started dogging me out and making up blatant lies to one of our mutual friends/coworkers and she enlightened me on things she said about me. Which was a lot but one thing she told my coworker was that she didn’t care if I didn’t like it or not, but she was gonna teach the baby every cuss word in the book because she thinks it’s funny. AFTER hearing me talk about how I didn’t find it funny to teach young children to cuss and that mine would be taught not to. Which isn’t cool to try and totally disregard my rules as his mother.

Let me also add that I come from a more conservative family who raised me in the same way. She and her brother (my bf/bd) on the other hand were not. Which is fine, whatever, but DO NOT go against me as his mother. Have your own kid if you wanna teach somebody cuss words.

With us being so close at one time, she KNOWS my family is a little more reserved & conservative and for my family baby shower she also brought some very vulgar and offensive onesies with words like “fuck” on them.... And when my bf mentioned it was disrespectful to do that at MY family’s baby shower, KNOWING how they are, she said she didn’t care cause the gifts weren’t for them.

And not only that, she knows I wouldn’t put that on my baby... but she got them and gave them to me and has sent me numerous texts saying she needs him to wear all of them “or her feelings will be hurt” and that I have to send her pics of him in all of them....

I just wanna tell her to have her own damn baby!!!

Sorry so long and so much to read but how do I handle this?!??

**UPDATE**

I also wanted to add this because I saw several of you commenting talking about how my boyfriend needed to step in. When I have brought it up to him, he says that I need to talk to her about it because if I don’t one day I’ll just let it all build up and blow up and it will be worse than if I go ahead and talk to her about it. And he says he doesn’t wanna be in the middle because he’s not gonna choose between me and his sister. Now, she is the kind of person you CAN NOT confront and have an adult convo about something she’s done wrong because she never sees that she’s done anything wrong and she immediately jumps on defense, turns it into a fight, and not only that but she becomes a very spiteful person and I KNOW it would only make matters worse. I know she would just continue to do more things except worse because she’d be mad and doing it out of spite.

So that is why I have no idea how to handle it or what to do.