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, TLIF at L4/5.
Feb 2012 major lumbar revision for broken rods @ L2-3-4
Aug 2015 rods broken L5, A/P revision 9/23
mom of Leah, 13 y/o, diagnosed '08 with 26* T JIS (age 6)
4/08 26 degrees, brace 16 hrs/day
9/08 17 deg. OOB - brace discontinued
9/09 30 deg, resuming brace
5/10 VBS Dr Luhmann Shriners St Louis
4/15 stable 5 yrs post-op, 18* T/ 22* L, Risser 2
also mom of Torrey, 10 y/o son, 16* T, stable