Can you tell me the ways scoliosis affects a girl's life?

Shorter. Shorter height, possible pain or shortness of breath, if bad enough.
Cosmesis. Scoliosis is largely a cosmetic problem (provided it is idiopathic). If severe, it can cause lower self esteem. Severe scoliosis (>50 degrees) is said to progress in adulthood by a degree a year. If the curve reaches greater than 90-100 degrees, respiratory symptoms may develop. As such bracing or surgery is often recommended in adolescence when the curve is flexible and more easily corrected.