Do girls get wedgies as well as boys?

Yes, more so than boys in real life. In fiction it is usually uncomon for unknown reasons, but in reality Girls are more likely to get wedgies due to two reasons.

Teenage girls are more likely to wear tight fitting pants and underwear, so they're more likely to have natural wedgies.

Girls are usually weaker than boys, so boys are able to give them wedgies considerably easier.