I think you are asking under what circumstances is someone extended term eligible. If this is your question then it would be based on priors so if there are none then the defendant is not extended term eligible. However, there are some mandatory sentencing requirements for this type of charge. The defendant needs to have an attorney.
This comment is being left for informational purposes only and based solely on the information provided in the question. This comment does NOT create an attorney - client relationship. An attorney should be contact directly and given the full details of the specific circumstances in order to be best able to assist in the issues at hand.
The Illinois statutes relating to Aggravated Sexual Abuse have several variables. To determine what class felony you have been charged with depends on age of the victim, age of the accused, whether there was a position of trust( teacher, coach, priest, etc.). If you are referring to an extended term sentence, it depends on the class felony and the accused criminal history.