The victim, 16-year-old Sarah Goone, was critically injured in the crash.
Monday, two misdemeanor DUI charges were added against Hughes after blood test results confirmed traces of marijuana were in her system at the time of the crash.
Hughes' court appearance was brief. She faces a felony count of leaving the scene of an accident with bodily injury, in addition to the two counts of DUI.
Goone suffered severe injuries and is still recovering.
Hughes had been jailed briefly, but a donor posted her bail.
She had no public comment Monday, but one of her attorneys spoke with ABC7 Chicago.
"Whatever charges are brought by the state, she'll deal with, but her main concern is how Sarah is recovering and her treatment and her therapy," said attorney Barry Spector. "She's a kid just like Sarah and could see herself in that condition, too. And anybody who knows anything about this case feels the same way. Everybody wants to see her make a recovery."
The felony charge caries a maximum of three years in jail. The possible penalty could have doubled if the original aggravated circumstances had stood. However, they did not.
Hughes will be allowed to leave the state for a short time to register for college. She will be back in court July 8.
At the same time, Sarah Goone continues a painful and difficult recovery.