Why on God's green earth would you take a child with the flu to the doctor's office? Just so you can infect everyone else in the entire office with the flu germ? That's ridiculous!
Grounds for termination! How long have they been with you? This is how it is worded in my contract:
Weekly fees are payable regardless of closed daycare holidays, missed or sick days. Fees are not due when the daycare is closed due to caregiver’s vacation or illness or emergency.
I would quote my contract to anybody who questioned me and tell them they read it and signed it and must abide by it, no questions.
GOOD LUCK!