I have it, along with kyphosis in my upper back but my curvature was never anywhere near 30 degrees.

My parents spent a lot of money on two different back braces, but I think what actually stopped it was that I simply stopped growing just before I turned 16.
This was in '90-'91, I'm not sure if they'll have her in a brace today but if they do, wear the damn thing!

It may have helped in my case, and of course she wants to avoid a metal rod back there if at all possible.
--T.J.