My four year old daughter just had an X-ray that says she has stable mild levoscoliosis. What does this mean. And what does it mean for her?

Consult a pediatric . Mild spinal curvature may not mean anything but without examining the x-rays it is a guess. Your best option is to consult a spinal surgeon or pediatric orthopedist to be certain that some treatment like a brace is not indicated. A follow up examination as she grows is essential.