What does the probation say?
Hey, I'm a newbie to the posts... I accidentally replied to this as a new posting... silly me!
Probation doesn't run out just because you turn a certain age. I am not a lawyer, but I would check the terms of the probation. If it stipulates that the probation perios is for a specific time (2 years), then age, I don't think, would have anything to do. However, if the probation was until a certain age (and I have never heard of this), then it may be.
I STRONGLY recommend you look at your copy of the court documents (and the sentencing). If you don't have copies, go immediately to your court and file a freedom of information act (federal reg. title 5 USC), or whatever local applicable public disclosure / discover laws are applicable, and keep your copies. Always keep copies of legal documents!
Last place - consult the probation officer.
Good luck and wish you the best!