There’s your answer right there. Your daughter has admittances to two great flagship universities, one with a bit more “prestige” to its name, but both are very good universities. You would require loans to go to Michigan. You would not for Illinois. The difference in price between the two would be about $170k or more, which is not an insignificant amount.
I understand that many seniors have a desire to go out of state because it’s something new or different, and they want to spread their wings. If you are willing, suggest that with the savings of going to UIUC over Michigan that she could spend a year studying abroad, or have stipends from the family for summer internships, or a single room in the dorms after freshman year, or special extras like season sports or theater tickets.