Thanks for your input, everyone. I have decided that I will tell the mother it isn't working any more, because, really, it isn't.

Just as an aside, she did not ask permission to take the apple. It's an apple, I know, but my reaction was also WOW.

I had words with her via text this past weekend. She hadn't paid me as of 11 am on Saturday, when fees are due by 6pm Friday. This happens regularly, as I said. She was squabbling with me about $10, and then suddenly, the $10 was no big deal, and I was splitting hairs. I told her firmly that from now on, even one minute after 5:30, she is charged the extra $10, and after 6:30, it'd be another $10 again. I also mentioned that it was a $30 late fee for payment past 6pm on Fridays, and that it wasn't personal, but that's what she'd be paying from hereon in. She didn't even have the manners to reply. Ugh.

You think after years of daycare, I'd learn not to do "special" as Judy says, and I'd have learned that my time is precious.