They're scheduled back in court on Oct. 10.
The boys, ages 15 and 17, are charged with carjacking and aggravated assault. The girl is charged with conspiracy.
Police say the girl set up the beating after she agreed to go out on a date with a male classmate.
The two boys allegedly committed the assault while the other boy sat in his car in a parking garage while the girl was gone. He escaped with minor injuries.