Mental health issues can caused by so much things and are very individual and if she might have problems, I hope they can be solved.
But what we all have to be aware of is that this is social media, this can cause problems by too much negative input, but! in most cases it shows things that are far away from reality to create content and increase the number of followers.
It might also create some mental health issues if those media is for monthly income and slowly the flow of money get drained.
I am not aware of what happen to all of those influencers when no one watches their content anymore and they have to look out for a real job.
For example looking at those feature dancers from the 90's, how much we love them and how we might thought they have a great life, but nowadays they might life in a trailer park and only a small number remembers their name.
I bet in 10-15years no one will remember those YT or insta influencers if they don't done real interesting content.
So increasingly common, especially in girls these days, for a host of reasons from social stigmas to self-images. Much of my entire extended family is in healthcare; two with psych degrees; so health/psych are a rather common subjects whenever we get together. When you have been in and around the field as much as I have, recognizing problem behavior becomes easier, however, it is all a guessing game as to the underlying cause until all the cards are on the table, which oftentimes is something the patient is either unaware or refuses to acknowledge.
If that's the real deal, I feel reely sad.
I am aware of what it meent to have a burnout, it doesn't grow over night or is a hard horizont, it comes slowly, each time it's putting some weight on you, till you miss the stopping point

.
But then I am not someone who tells everyone out there my whole story, it's kind of a very private thing.
I didn't make it puplic to the whole world to people I don't know as if they could help me. Sure I also was kind of ashamed of this situation and had fear how my family or people at my work react.
And so I would expect her (or other social media creators) to only write some short sentences, like she didn't feel that well, to make new content and need a break and that's it.
But maybe I am kind of different in such things.