I would give anything if my son were 16 again. I don't care what it took. Pulling him out of school, taking away internet, phones, etc. I would find a way to let him know how precious and perfect he already was. You have two more years that she is still under your control. Even if I had to move away. I don't care where to, I would do it. I would do anything and everything it took to help them see that there is no such thing as "trans," even if I had to physically restrain him. Thats no different to me than keeping him from running into the street as a toddler. If their minds aren't mature enough to listen to reason, then they'll be treated as such. Treat this like her life depends on it, because it does.