I personally don't think her going home reflects her privilege. It's a shame there are students who won't be able to, for whatever reason but Ruby should not be made to feel guilty as that is not her fault. When I was at uni, my student loads covered my rent meaning I wasn't spending any of my own money on it, it was the same with a lot of people I knew. She may be paying for a place she's currently not staying in but that doesn't mean she's wasting her own money, thats what student loans are for. Some students at various unis were forced to rent somewhere despite classes being fully remote otherwise they couldn't enroll, how do we know she wasn't promised some in person teaching which changed to fully remote?
I'm sure a lot of people posting here, if given the option and the means just like Ruby has atm would go home to be with family during all of this. I know I would.
We don't know if she moved to uni in the first place because she thought she could handle it, has struggled with the isolation aspect of it or the anxiety of being in a big city (she's rural to be fair) and has decided for her mental health it was better off her living at home instead. The list of things that could have happened it endless tbh but until she clarifies why I don't think it's fair to call her immature or privileged and to make her feel guilty for going home.