Age of Majority / School & a mad judge (at attorneys, not parents)

[Qofprinciple]

Okay, we took advise and hired an atty when child reached 18 and was expelled from school for smoking marijuana on school grounds to file an abatement of child support (child was also working full time during expulsion).

State child currently lives in has agressive, no dropout policy so offered alternative education.  BM stated child was enrolled in program but only offered a school transcript of child being UNenrolled (before 18th birthday) and a vocabulary lesson work sheet dated 2 months after date of expulsion and stated, child only worked 3 weeks full time before quiting job.

Short story short...judge was livid that attorneys would waste our money to bring this issue in front of him...if kid in school not working full time then CS should continue.  Which I do agree with.  If my CS keeps him from dropping out of high school, hooray!!! Problem is attorneys pushed for Agreed Order without any proof child enrolled in any school program... my feeling is so that they could get this off court docket and out of judge's scrutinty.  BM and her atty are not providing any information of school enrolled in and last school of record does not have a school record transfer request to new program.  

In short, neither of us live in Illinois anymore but are dealing with an Illinois CS order on which Illinois retains jurisdiction.  My atty is getting court ordered school records but this could take many months to straighten out and not to mention more legal fees to be paid out for the noncooperation.  And you know as well as I, if I overpay my CS because I "understood" him to be enrolled in High School but he wasn't then it is my loss.  

My question is one I cannot find in statutes but want  to avoid monies owed, atty fees and aggrevated judges:  how long does a child in the age of majority have to be unenrolled from school to be considered emancipated or am I just stuck paying for him till he is 19 because he might go back to High School at some point during this final year of his CS?

Clarification:  old divorce judgement, have to pay CS through high school up to age 19, otherwise 18.  Visitation Interference and not allowed phone contact for 11 years so child no help with worthwhile information.