SheZow.

A 12 year old boy named Guy Hamdon, discovers the superheroine Shezow's power ring and puts it on. While the power ring does grant him super powers, it was only meant to be worn by a woman. Guy takes on the appearance of a female super hero and with the help of his sister, Kelly, and best friend, Maz, he protects the city of Megadale from supervillains and criminals.