Hi resilience,
Like Chris above told you, you know your child best and know how much to tell her. In my personal opinion, I always try to tell my kids the truth in a way that they can understand and is age-appropriate for them. Kids always know when their parents are trying to keep information from them, and really it scares them. They think, If this is so scary that Mom and Dad can't tell me about it, it must be terrible. I think this can allow sensitive children in particular to have their minds run away with them.
I was completely truthful with my daughter when she was diagnosed at 6. I tried to explain everything to her in a way she could understand, which is definitely tough at these young ages. I told her she had a choice of wearing her brace for 8-9 years, or that if she wanted there was a surgery (VBS) that might allow her to be out of the brace. I think it is a big mistake to use the possibility of surgery as a threat to force brace compliance, because if you make surgery out as a negative thing, what do you tell her later if it becomes necessary? This is especially true with JIS kids who have such a high likelihood of surgery. My daughter truly hated her brace from the beginning, and so for her she always knew she wanted VBS, which she had very successfully this past May. She did amazingly well with surgery and returned to school 10 days after her surgery, no problem. Peace has returned to our home because there is no more arguing or tears about the brace. It was a good choice for us.
Like Chris said, each child and family are different, and I am sure you will find a way to answer your daughter's questions. For my two cents worth, I would really try to find a way to give your daughter the information she wants and deserves to know. It will make things easier later.
Good luck, it sounds like you are doing a great job so far. I think it is extra hard on us mothers who also underwent scoliosis treatments, to now have to see our children enduring them. I know this has been the case for me, definitely.
Gayle
Gayle, age 50
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, 15 y/o, Diagnosed '08 with 26* T JIS (age 6)
2010 VBS Dr Luhmann Shriners St Louis
2017 curves stable/skeletely mature
also mom of Torrey, 12 y/o son, 16* T, stable