Seconded. Mint with Timeshift setup. Ideally separated drive dedicated to this but you could make a partition.
With auto daily/weekly/monthly options and versioning you are pretty safe unless she has an axe.
I would also setup RustDesk so you can help if needed. But visits are nice depending on cookies and distance
I found it painful keeping track of what cable could do what and some screens/drives were picky.
I have nothing to do with it this but bought one. (I also have a cheap one that’s more generic but doesn’t give anywhere near the same amount of information on cable health.)