This really strikes a nerve with me because I have your family's clone!!! If your policy says stay home for 24 hours after fever has broke and he had a fever last night that means they can't come until Monday. If the dr gives a note "say great, I will see you on Monday then." No doc is going to tell me to break my sick policy. Once I had to tell a family with a doc's note "my sick policy is clear: 24 hours with no fever with no meeds and if the doc wanted to provide childcare for the day she could"
I don't text with parents. You might send a quick email. "I hope x feels better soon. See you on Monday." Attach a cute pic of x having fun at daycare. Then don't respond to texts from them. They can call and leave a message if they REALLY need to talk....otherwise it will keep until Monday.