My first thought is: can 1 person legally care for 7 kids?
These are the legal requirements in Illinois:
http://ccrs.illinois.edu/providers/licensing.html
As a general rule of thumb, if the number of unrelated children you provide care for, is more than three (including your own children under age 12), you will need to obtain a child care license from the Illinois Department of Children and Family Services (DCFS).
The above website has a lot of detailed info. You, your home and the kids you care for have to meet certain requirements (age, inoculations, space).
Before something bad happens with this many kids in your home, I would make sure you meet the law and have the appropriate insurance. I would also have written contracts with parents so there is no misunderstanding - do they still pay you if a kids is sick and does not show up, what about when you or your kids get sick? I have heard too many stories (even on this site!) of watching a friend's kids and at one party feeling like there is no reciprocation or sufficient acknowledgement or payment.
Hope for the best but plan for the worst.