My daughter does not have congenital scoliosis, rather she has juvenile, so I have no personal experience with hemivertebrae. However, I took my daughter to see Dr Betz at Shriners Philadelphia (and we traveled 3000 miles from Oregon) and he is certainly among the very best. I imagine in your daughter's case it will be a very valuable third opinion.
Good luck. It sounds like you are doing a great job getting all the information for your daughter's surgery.
Gayle, age 48
Oct 2010 fusion T8-sacrum w/ pelvic fixation
Feb 2012 lumbar revision for broken rods @ L2-3-4
Sept 2015 major lumbar A/P revision for broken rods @ L5-S1
mom of Leah, 14 y/o, Diagnosed '08 with 26* T JIS (age 6)
5/10 VBS Dr Luhmann Shriners St Louis
5/16 6 yrs post-op, 24*T/ 22* L, mild increase in curves
also mom of Torrey, 11 y/o son, 16* T, stable