I have had two young clients (15 and 17) with idiopathic scoliosis and their programs had to be substantially different due to the differing degree of curvature, one had a single curve the other a double, and also the location of the curve on the spine were far apart.
Both had bracing and one surgery...both are doing great!! Since you are in the very early stages, all this must seem surreal and a little more than scary to you...both sets of parents of my young clients said things got much better once they learned all they could and assembled a good team of doctors to oversee the protocol!
Once cleared for exercise, I would recommend one or two sessions with an instructor who can get the basics of movement down with your daughter before she tries a class or dvd. They will encourage good form and movement to keep the body and mind safe and healthy...maybe you could do the training together to cheer each other on!
While the internet can be a great source for information what is out there can be overwhelming and easily misconstrued....know each child has a different situation and there is no one cookie cutter case. You are your childs best advocate...armed with information pick best specialists you can find to partner with...even if you have to stand up to an insurance company/person or two!!
Happy Training!