My niece has a coin shaped rash on her right buttock that is scaly in the middle, but it's not itchy. could this be a ringworm?

Possible: Generally, I think of ringworm when a lesion has clear center and raised edges. Could be a dry patch of skin called nummular (coin) eczema - this is usually flatter at edges and scales in middle. When in doubt best to have MD look to be sure. Consider using Lotrimen until appt if no sensitive skin problems. If ringworm, it will help. If eczema, the base lotion in cream may help. http://www.medicinenet.com/ringworm/article.htm