Legal Question in Family Law in Illinois

I would need to know more before giving a complete response. Generally, the rights of natural parents are always greater than those of grandparents. There is no such thing as "sole physical custody" - "custody" is the right to make decisions about children including health care, education, and religion, among other things. "Residence" or "Residential Possession" or "Residential Custody" is simply where the child lives primarily. You don't explain whether this arrangement is the result of a court order, an agreement, or otherwise. In a generic situation, the natural parents should be able to do whatever they want with their own children unless barred by court order (due to abuse, neglect, etc.). Hope this helps.