My heart goes out to teenagers having to get through these horrible times. Not able to 'hang out' with their friends, not even able to 'escape' from their homes during school times.
Having brought up seven children including four girls, I have to admit I did hate the teenage years. Can well remember when the last one turned 13 yrs I actually said, that I could do this again.
Obviously really rude and nasty behavior cannot just be ignored, but in these times I would think long and hard before taking away the 'phone from this youngster. It is in the present circumstances, her only connection with friends, etc.
I had some dreadful teenage traumas with mine (girls were definitely worse than the boys). The ones that had their really bad years early in teens were actually easier to cope with than the one who was lovely until she was 18 yrs old and then started. Obviously, I had no control over her at that age, and when I used to her those silly word 'Not whilst under my roof......', she just upped and left!!
At least with 13 year olds you have some control. So, do not make a battle out of everything - just remember the conflicting feelings racing around in her hormonal head. Be loving and sympathetic and ' be there' when an occasions arise when she wants to come and talk and/or be a child again.
Just to say, we all did survive. All have turned out into loving, caring adults. The one who caused me so much heartache in her later teens has apologised so many times to me for her behavior then. She threw away her chance at that age of getting into Uni.......messed around for a few years and then settled down in her late twenties. Got a great degree, a superb professional qualification, and now, at 50 plus years old, is a very high flyer in that. So, do not get too hung up on missing opportunities.