Annulments are a matter of state law.
Your friend need to consult Illinios law on the issue. An annulment or nullity treats the parties as though they were never married. The relief is typically availabel in only limited cases involving void or unlawful unions i.e. incest, bigomy or voidable unions where there is a defect in freely consenting to marry, i.e. minority, fraud, duress, unsound mind. Your friend was a willing participant to the marriage so fraud cannot be claimed form the facts given. Have an attorney in Illinios review the matter.