I do feel for her that uni hasn't been great for her and I do agree that it doesn't have to be the best time of your life but also she is an adult now and that means doing stuff you don't always enjoy and feeling uncomfortable sometimes, it's how we grow as humans. Not saying she has to drink or go clubbing, I don't do that but I still enjoy seeing people even though i'm introverted it just means if I've done stuff a few days in a row I get overwhelmed and have a few days alone but she never does anything to push herself beyond going for tea and book shopping, anything outside her comfort zone scares her. I find it cruel she won't even visit Marfa who is up north without her family, Ruby could easily make a nice weekend of it she has the money to book a nice hotel, she wont even have to stay with her.
She was in that harry potter society in first year, beyond that I've never seen her socialise in a setting she isn't comfortable with. A job would really benefit her but I can't see her going for one. She's got way too used to having a nice big house, attention, money and loving parents and now she doesn't have all those things 24/7 she cant cope, which I do understand to an extent, If I came from a neat little world into a world where things are new and not used to it, I'd also get uncomfortable and scared but she isn't doing anything to help how she feels.
It's ok to be home sick but not all the time? It's not healthy to feel any one thing every single day