Would you charge a late fee for daycare fees that are due on Monday morning but dck's (siblings) were sick and did not attend until Tuesday.

DCM brings kids this morning (without payment which was due yesterday). I'm planning to charge her for today (late fee) but what about yesterday? Her kids were sick and she kept them home, but I know other providers require parent to still drop by and bring payment. What would you do?

Yes I have a contract. Iron clad. But I'm wondering if I should waive the fee since they didn't come yesterday.