... and not just leave it for the next child who comes along.
Had to pop into the school toilets after dropping DS at school as DD1 (3 yo) needed a wee. In there was a girl in DS's class coughing and throwing up into the sink. I asked the Mum if she was poorly again, as she came into school 2 wks ago having spent the night vomiting but "she didn't want to miss anything so I broght her in anyway". Mum replied that no it was just phlegm as she's got such a bad cough. Thought nothing of it, turned to DD1 to help her with her tights. Went to wash our hands to find the sink that the girl had been using had milk and phlegm vomit all round the bowl! WTF! Is it really too much to expect you to clear up after your daughter or even show her how to rinse the sink herself?
Good manners aside surely you'd tidy/clean up for hygine reasons.
Rant over.