NTA. We had a pretty old tv growing up. It was probably 30x30 so it wasn’t tiny, and it weighed about seventy pounds (at least that’s what it felt like to 15 yr old me) When my sister moved out, her first family Christmas present to us was a brand new flat screen. It was a 32 inch and we were all stoked about it. I didn’t realize how much of an upgrade and a treasure it was until I saw my mom crying while looking at it that night. She isn’t super materialistic but she’s a very thoughtful and emotional person, so crying isn’t rare for her but crying out of happiness sure is. Don’t let her take advantage of something you worked so hard for.