I get 10 paid sick days per year.

If my kids are sick, it depends on what they have weather or not I close or remain open. It is my business so the parents can NOT tell me when I should be open or closed. If I am open they have the right not to bring their child, BUT they still have to pay for the day.

I would stop bending over backwards for them and start advertising. If you can find replacements then get rid of them. They are taking advantage of you and you deserved better.