my mum said she first noticed that my back seemed curved when I was about 3yrs. she took me to the GP a few times over the next few years and was always told it was nothing, I just has bad posture. she was continually trying to get me to stand up straight and not slouch when sitting (I now know this is one of the early warning signs).
I never had any problems (other than how I looked) until I was in my mid-20's. I was living in England and went to at least 5 different GP's before I was finally referred to a rheumatology consultant who diagnosed my problem as Scheuermann's Disease. the only thing he could ofer was physiotherapy, this wouldn't cure the condititon but would make it easier to live with.
From reading on the web I think the problem is best dealt with at about 11 or 12yrs, with a "milewake brace" worn for most of the day for a while. once the spine is fully developed (ie an adult) there is no treatment that I've heard of yet.
there are a lot of conditions which are similar to this..she may just have bad posture? I would take her do the doctor just to be sure (although no GP I have ever been to has ever heard of this condition!). I suppose keep an eye on her until she reaches her teens and she if improves or worsens.
At the moment for me:
overly curved spine
kind of a hump back
bum sticks out
belly sticks out
small of back...noticable very curved...if I lie down, you can place a huge fist under the small of my back.
hope this helps.