Hi Tippyboat,
I'm an OOS M1 at UIC currently trying to establish residency. I met with the residency officer during orientation and it sounds like you are in good shape to petition for Illinois residency if your parents are currently residents of IL. From my conversation with the RO, it sounds like whether you are dependent on or independent from your parents should not have an impact on your ability to obtain residency through them. He said that as long as they are residents (pay IL income taxes, registered to vote in IL, etc.) then you would be considered a resident.
If you wanted to obtain residency on your own, it would require you to work and achieve a certain level of income for the year prior to when you want to become a resident (I think it was >$12,000, but I don't remember the exact number anymore). However, I think it would be hard to put enough time into working that many hours to meet the income requirement and have time to study.
Here is the link that UIC has for residency requirements for more information:
http://www.usp.uillinois.edu/residency.cfm
It has a lot of legal jargon so I would recommend contacting the office directly to speak with a residency officer directly. From my brief conversation with him, I got a lot of helpful information and they sound like they are very open to helping students obtain residency. Hope this helps and good luck!