Hello ......
I heard someone a few days ago on a TV program state daughters are a lot more difficult to deal with than sons.
I have two daughters. Both are adults - so, of course, both were 15 at one point in time.
I think it's totally reasonable to say that a 15-year old has very little idea of what is best for her. She knows - she thinks! But, it just ain't so!
You mentioned a therapist - and that could be anything from a pill prescribing 10-minute psychiatrist to a Social Worker - and lots in between. If it was a talk psychologist, I don't think you would have written this thread. They usually are very helpful - as long as the patient is willing to accept help.
You mentioned a medium. I happen to be very interested in alternate concepts. I went to a legitimate professional once who was interesting ... but NOT for depression. That's like going to a chiropractor for a toothache!
Many who are depressed - end up trying different types of meds prescribed by doctors - before finding one that works. It's not an exact science.
And grief counseling is an excellent idea for anyone who has had a loss. With a 15-year old, I believe it can be even more traumatic than with an adult. Latitude for a 15-year old is good .... but you are the boss! And the decisions you make for her are for her best interests. That's what we do as parents!
Peace and wellness
Rob & Gizmo