Hugs to you and her!! I had scoliosis surgery done when I was 9 for a double curve - Harrington Rod fusion, this procedure from what I understand is no longer done BTW - and it was hard the first few months afterward because of the activity restrictions, but am glad I had it done then, hearing about how those who didn't do it are now suffering. I also had a torso brace to wear for 6 months post-op (not the Milwaukee brace). I had pain and a bit of post-op bleeding the first few weeks but it eventually went away.
I realize that kyphosis is a bit of a different animal and that everyone's experiences are unique so YMMV, but I can tell you now (25 years post-op) that the day-to-day issues I have run into are due to the fact I had my surgery so young that it stunted my torso growth, not so much from the surgery itself. I'm short and my clothes fit funny!

Personally, I don't live with chronic pain from it thankfully, although I do get muscle spasms from time to time since I've had my kids. Flexeril and I have become good friends from this

. I was pretty watchful about how my scoliosis and subsequent surgery could affect my pregnancies and deliveries. I had a failed epidural during my first L&D but made sure the second time around that I had my x-rays to show the anesthetist, and went with a spinal block, which was successful. Both my girls were c/sections out of necessity due to the growth stunting from the spinal surgery. I know that pregnancy is not an immediate concern, but it's always something to bear in mind for the long term.
Where on her back is the curve if you don't mind me asking?