My mother is in her 90s. She has never watched tv. My brothers girlfriend wants to put a tv in my Moms sitting room for her to watch movies on. My Mother has never watched tv. Never been interested in it. And I don't think she will be able to sit up long enough to even watch a movie. My mother usually sleeps most of the day. Ahe has had parkinsons for years. I just don't think the change will be good for her.
BTW, she has a TV in all the rooms but the bathroom, and that's only b/c it's not cabled for one. If your mom liked TV that would be one thing, but she doesn't, so don't bother.
I know it seems weird to us, these quirky behaviors, but we need to respect our parent's "stuff".
Now rearranging an elders pocessions or living areas will cause confusion and distress
Though your brother's girlfriend might do better to save her money... Still! It's her money! Just warn her she's probably wasting it.