That could also be sensory issues, tbh. I was also a teenager who hated showers, and I'm pretty sure it was based around sensory issues. It's not something that tends to get accounted for unless the kid already has an ASD diagnosis, and often not even then.

(Also, I am wondering about a teenager who has violent tantrums to the point that her mother is afraid of her who gets assessed as having "no mental issues". That... seems wrong. Normal teenagers should not be having frighteningly violent tantrums at their parents.)

"Making their life so miserable that they treat you as a jailer" (which is often what 'taking material stuff away' comes down to these days, especially since the first 'material thing' somehow always seems to translate to 'ability to communicate with friends') can fix things like that in the short-term, because it changes the scale they measure misery on, but it doesn't tend to help long-term.