WIBTA if I told my sister she can’t have her baby shower at my house anymore because she keeps inviting people without asking

My sister is pregnant with her first kid. When she started talking about having a baby shower, I offered to host it at my place. I’ve got the space, she doesn’t, and I figured it would be a nice way to help out. She told me it would be a small thing with about 15 people. I was totally fine with that. I started planning for food, chairs, space, and all that.

But over the last couple of weeks, she’s been texting me with more and more names. Friends from high school, coworkers, people from her boyfriend’s family. It’s up to around 40 now. Most of them I don’t even know. She never asks if it’s okay, just keeps saying it’ll be fine and we’ll make it work.

I tried bringing it up and told her my house really isn’t built for that many people. She brushed it off and said I was overthinking it. I told her straight up that if she keeps adding people without checking, I might not be able to host it at all.

She got upset and said I was being selfish and making her feel like a burden. Now our mom is telling me to just suck it up and be flexible.

But honestly, I’m already paying for most of the food and doing all the setup. I didn’t sign up to host something this big. I feel like she’s taking advantage and just assuming I’ll deal with whatever she wants.

WIBTA if I told her she needs to find a new place for the shower?