I have a dd2 with a scoliolis. It is the descriptive term for the shape of her back, and can be caused by differing factors.
This is what I have learned so far:
We all have a natural curvature to some extent. Nobody is plumb straight.
Some scolioses are postural and straighten when you lie down or are suspended (thats how the Consultant diagnosed it!), some have an underlying bone problem.
Some can be corrected or improved by exercises, others you just live with.
Surgery is often only considered if the scoliosis is causing other problems, eg restricting the use of arms due to shape of spine/causing serious chest health issues due to compression.
Surgery can be very uncomfortable and not always successful as it usually involved fusing bones or inserting metal rods.
Don't panic. It may be mild and she may well cope fine with it.