I'm sending you supportive hugs and pats on the back. It's so hard to know what to do, sometimes you get conflicting advice and you are expected to make all the right decisions at all times. It stinks.
I think the fact that she is cooperative about medications is fantastic. That is huge, in my opinion, because that is something I could never get my difficult child's to do, nor get support from their dad. I would make a point of telling her how proud you are of her for being mature enough to know that she needs to take responsibility for her self-care.
I agree with-you about the cell phone, she has to earn your trust to get it back. My ex has blocked certain phone numbers from our son's phone (kids he suspected of enabling our son to smoke weed, etc.) and it is a PITA to the child. some of his more persistent friends will call his older sister, and they all get a tongue-lashing from her for using up her minutes! It has discouraged him from being in contact with certain kids.
My ex and I were roundly criticized for bringing our son home after six weeks in a diagnostic Residential Treatment Center (RTC), against their advice to have him transferred to another Residential Treatment Center (RTC) for long term support with his dual diagnosis. I questioned our sanity. However, he's been home three months now and although he has slipped up and smoked weed a couple of times, he is tested regularly and has to answer to his PO, who made it clear that if he fails one more test he is going to SA treatment inpatient, something that he really doesn't want to do, and she has the power to make it happen. So there is a consequence. He is actively searching for a part time job, just got his water safety/safe boating certificates so he can start using the boat he helped rebuild, and wants to apply to a magnet high school in our district that specializes in information technology and engineering (college prep currciculum but electives are all geared for sciences). I'm willing to give him the chance to show us that he is committed to turning his life around.
Most kids, if they have a good home to come back to, do not want to stay in an Residential Treatment Center (RTC) or psychiatric hospital. My son met many kids at his Residential Treatment Center (RTC) in PA that had been placed in group homes, hospitals and RTCs for very long periods of time, who had no real parents and no structure at all if they returned to their nearest relatives. It's so sad. My son cried for the first three days when we left him in PA but he was so anxious to get out he obeyed all the rules and made sure he would be eligible for discharge after six weeks. but he also knows that if we think he is at risk, we won't hesitate to do it again.
Keep us posted on how things are going at home. I will keep you in my thoughts and prayers for strength and courage.