Hello corgidogs: I see this is your first post here on PC. Welcome to Psych Central. One additional forum, here on PC, that may be of interest to you would be the Partners of People & Caregivers forum. Here's a link:

https://psychcentralforums.com/partn...ivers-support/

One thing you didn't mention in your post was the age of your granddaughter. However, based on what you wrote, it sounds as though she is perhaps a teen? You also didn't mention where you live. I presume, since you mentioned the school agreeing to take your granddaughter back "after a lot of pleading from her parents", that they perhaps do not live in the U.S. unless this is some sort of private school. Any public school in the U.S. would, I believe, not have the option of simply refusing to take a student back due to the student's mental health issues. (Also I don't believe public schools in the U.S. require uniforms.)

It's difficult to know what to suggest to you regarding the situation you describe. Although your granddaughter is presumably still a minor, she's clearly old enough to exert her own independence. (She's not going to simply do what someone tells her.) Our host Dr. John Grohol, Psy.D. has an article, in Psych Central's archives, that touches somewhat on this subject:

Denial is a Powerful Impediment to Treatment

It is also true that some individuals who have mental illness simply do not recognize they are ill:

How to Help Someone with Mental Illness Who Does Not Want Help | What is TMS?

You mentioned your granddaughter seeing a psychiatrist. You didn't mention if she is seeing or has seen a psychologist or mental health therapist. Here again, I don't know where your granddaughter lives. But where I live, all most psychiatrists do is to prescribe & monitor psychiatric medications. All therapy, or counseling, is left primarily to mental health therapists. When I was seeing a psychiatrist I would be in-&-out of his office within about 10 minutes. That didn't leave much in the way of time for discussion. So, depending on how these things work where your granddaughter lives, having her seeing a therapist or psychologist on a regular basis (once she's out of the hospital) may be something to consider.

One additional point I thought I would mention, since your granddaughter is hospitalized, is that coming out of a psychiatric unit right back into the same day-to-day situation the person was in prior to being hospitalized can be difficult. In some areas, at least, there are what are referred to as partial hospital programs where a person lives at home but attends a day program up to 5 days a week for a period of time. Something such as this might be advisable for your granddaughter in an effort to smooth her transiton back into day-to-day life. Beyond that, I'm afraid the only other option that would occur to me would be some type of residential mental health treatment facility. Perhaps other PC members may have other suggestions. Here are links to some additional articles, also from PC's archives, that may be of interest:

11 Ways to Help a Loved One in Denial

How to Persuade Your Loved One to Seek Professional Help

https://psychcentral.com/lib/15-ways...illness/?all=1

I hope you find PC to be of benefit.