They will want X-rays for comparative purposes; this allows them to track progression of the curvature over time so they can determine how aggressively to treat your daughter.
My daughter was diagnosed at the age of 9, and her curvature progressed quickly in spite of bracing. By 12 she had a 65 degree curvature, and it was decided that surgery was the best option. In the 8 months between that decision and the actual surgery, her curvature progressed to 91 degrees. The surgery fused 8 vertebrae together and used the traditional rods and screws to reposition the spine to allow the fusion process to take place. She literally grew 4" taller on the operating table, going into surgery at 4'11" and "growing" to 5'3" post surgery.
Now 18 years old, she's doing very well and faces few limitations. She ran XC and track for a few years post surgery, and while not a fast runner she suffered no back pain as a result.
My best advice is to seek out the most experienced scoliosis practice in your region, and do not be afraid to seek a second opinion. Should it come down to surgery someday, are very few surgeons that truly specialize in this condition, and those that do are far ahead of general orthopedic surgeons in successful outcomes.