The reward is being raised from $3,000 to $5,000.
Recently, Chicago police admitted there had been misconduct while the case was investigated.
Family and friends announced the new reward on Thursday, just yards from the home where she was last seen.
"There was forced entry to this basement room area and of course to us that's compelling evidence runaways don't cut locks and force their way out," said Rev. Cy Fields, The Leaders Network.
Clergy members and area residents handed out flyers in the neighborhood.