Wow. I’m so glad I read the whole thing. Thanks for sharing. That is heartbreaking — your daughter, and of course your brother-in-law. I can certainly see why you’d be so terrified and hesitant about meds. I’m certainly no expert, but I thought I could try to help.
This may sound odd, but I think it’s a good sign your daughter is asking for meds. Your daughter is amazing! She has a lot going for her already! So of course it makes it all the more difficult when things aren’t going well for her in school and how she feels about herself. I think it’s a good sign she’s asking for meds because that means she’s self-aware and open enough (as a 15 yr old!) to know when she needs help, and to take ownership of her problems, and knows who and when to ask for help.
Since you/she are already doing a lot of non-medication treatment so well already, I’d say try the meds. Explain your very valid concerns to the doctor. They should help you with questions and let you know which meds have which risks and side-effects. I put off trying meds for my son for a long time, but we’d pretty much exhausted what we could do with non-med treatments, and still needed some help. That time was a very valuable learning lesson, and I don’t love some things about the meds, but they do help and make things all around better than without. Also consider the fact that many people will turn to “self-medicating” through illegal drugs/alcohol and high-risk activities, if they don’t get the help the need (though your daughter seems at low-risk for that).
You could ask your doctor about trying medications like Intuniv or guanfacine, or Strattera, that are non-stimulants and seem to have milder side effects. We are currently liking the liquid Quillivant (a stimulant), partly because of very flexible dosing. Also, you can look into getting her DNA analyzed for which medications are more compatible or potentially dangerous for her. The pediatrician’s office did a saliva swipe and sent it off to a lab (like for geneology DNA testing), and the insurance paid for it.
Also, make sure you’re seeing a good psychologist as well, and perhaps get a 504 for her for school. Those can help a ton with dealing with the little but important adjustments, tricks, etc., for coping with it all, and finding things that help fill in the gaps where help is still needed, whether using meds or not.
I wish you all the best!