What size should girls be wearing in middle school?

There's no single "right" size for girls in middle school. Clothing sizes vary widely between brands and styles. A size 8 in one brand might fit differently than a size 8 in another. It's best to shop by how the clothes *fit* the individual girl, rather than focusing solely on the number on the tag. Factors such as height, weight, and body shape all play a role in determining proper fit.