Prosecutors said the offenders attempted to rob the 17-year-old girl of pot.
Officials allege Avdic planned the robbery and Ly suggested the 17-year-old girl.
Avdic set up the drug deal via text message and drove Hughes, Smith and another person who has not yet been charged to the 9200 block of Kedvale Avenue, where the shooting took place, prosecutors said.
Gadau was shot in the back and the teen girl was shot in the face. The girl remains hospitalized and is on a respirator, officials said.
Prosecutors said Sunday the group smoked pot as they drove away from the scene. They also said the alleged shooter remains on the loose.
Patricia Gadau said at least two of the teens charged were friends of her son.
"It was hard for us to know that two of the youths involved were friends of my son," she said. "It was hard, very hard."
Patricia Gadau said one of the teens was even on the same swim team as her son at one point.
"They've both been to my house," she said. "I don't believe they knew it was Max. I think that they're crushed."
Hughes, Ly and Smith were ordered held without bail Sunday afternoon. Avdic is scheduled to appear before a Cook County bond judge Monday.
An attorney for Nicholas Smith, Edgar Howard, said his client is innocent.
"He was just a passenger in the car," Howard said.