My mom’s going to ruin my prom dress!

So this past weekend I went prom dress shopping to a boutique with my mom and a couple of my friends. We spent about two hours searching before I found two dresses that I was really back and forth between. When I tried the first one on, it was definitely nice, but it was kinda right and it had a halter neckline (which I wasn’t a fan of). My mom loved it though mostly because it didn’t expose the girls. She’s been really strict about the clothes I can wear since I started going through puberty. I have bigger boobs and thighs so she doesn’t let me wear shorts or v-neck shirts at all. So even though she loved it, I wasn’t too sure that I wanted to wear it to prom. The second dress was absolutely beautiful though. It fit me comfortably, was a stunning color, and most of all, I liked it the most on me. The only thing was, there was a small bit of cleavage which my mom was totally against. But somehow I managed to convince her. So I got my dream dress and I was really happy until she’s now insisting on putting a mesh piece in the front. I saw some of the other dresses at the boutique with a mesh piece and I think it totally ruins the look! Idk if I’m being dramatic but pls someone let me know how I can convince her to keep it!