I was going with her knowing when he would be out. However, I did consider having her not know (perhaps because she never found out what his sentence was; she didn't care and was just glad he was going to jail). I also considered having him get out early on good behavior, but I wasn't sure it's possible for a sex offender to get out early. Sex offenders can get out at their earliest release date providing they meet the requirements. Usually the requirements involve the defendant admitting to the offense and meaningfully participating in sex offender counseling. There may be other requirements imposed either by the court or the prison system.
Illinois appears to use a minimum and maximum sentence. For instance, a defendant can receive a minimum sentence of 3 years and a maximum sentence of 7 years. This means the defendant must serve at least 3 years and no more than 7 years. There may be good time credit involved in the minimum as well, but I don't know.
If the defendant is of good behavior in prison, meeting the requirements he had to do in prison, and meeting the requirements for parole, then he can be released after he serves three years as soon as he convinces the parole board that he has met those requirements.
Also, you made me think of something else, Jim. The way I currently have the story written has the MC not testifying in court because the guy admitted he did it. Also, there was evidence found at the guy's house (a broken necklace and ripped shirt). Is that realistic or would she have had to testify anyway? If the defendant admits to the crime, then there would be no trial, but a plea bargain, or more technically, a plea and sentencing. At a plea and sentencing, the defendant goes before the judge and says that he is guilty. At that point, the judge will ask the prosecutor what facts the prosecutor would rely on at trial to proof the State's case.
The prosecutor then recites the facts of the case (just in case the prosecutor doesn't actually have a case). Defense counsel is asked if he/she agrees with those facts. Defense counsel agrees and that's it. No testimony. No exhibits. Victim doesn't have to even go to the courthouse.
Plea and sentencing is by far the most common outcome in criminal cases (something like 90% of all criminal cases end in a plea agreement). Criminals are often overwhelmingly guilty and not completely stupid. Defense counsel gets to see what the State has for evidence. Plea negotiating is based upon the strength of the State's case. Good case and the defendant gets close to what he would at trial. Iffy case and the defendant gets a lot less. But pleas take less than an hour while trials take at least a half a day or more. Courts are backed up and everybody wants things to move as cheaply as possible.