It’s a fool’s errand unfortunately. Users stay in spaces because their friends and social circles are there. It doesn’t really matter how shitty the platform becomes. The social cost of moving is just too high.
The solution is interoperability and some regulation. Unfortunately we have neither. All you can do is inform your mom about the dangers and teach her to recognise propaganda and abuse.
Would recommend reading Cory Doctorow’s book ”Enshittification”