A lot depends upon the sympathies of the judge and the prosecutor. Hire an attorney for her - one who is experienced in traffic court in your location. Sh most likely will get supervision and a fine.
This is a minor traffic citation, but due to her age and I suspect being an insured on your auto policy, you should consider getting a criminal defense attorney to represent her. I don't practice in IL, but in my state, a sweet talkin' lawyer might get it dismissed with a reprimand or amended to a non-moving violation or referral to traffic school to avoid a conviction and points on her license (if you have a DOT point system in IL).
I am trying to give you a general answer to your question. We do not have an attorney-client relationship by this response on the avvo website. I have not been retained to represent you. I am licensed to practice law in Kentucky and in federal court in this state and the Southern District of Indiana. You need to seek legal advice from an attorney licensed to practice in your area..