Tough Love

Today was a first in many ways. Not the first time I've had all three kids out of sorts with me; that happens quite regularly, at least every Saturday when I pull out the list of housecleaning chores they need to help me with. Not the first time I've had to speak sternly with them; they're kids, after all, and prone to mischief as much as any others. And not the first time I've had to take the first two to task for school-related issues.
But this afternoon was the first time I've fought two battles in which I felt like I had the losing side, and I know I should not have.

Let me backtrack a bit, and break it down from the theoretical to the real.
It all started yesterday afternoon. Lauren caught me as I was paying bills (one of my least favorite things to do) (and to make it worse, just before she came to talk to me, I encountered two serious errors in my reckonings...ugh), and she had that look on her face that, for a parent, hints at trouble to come. She opened with a wheedle and it nothing much improved after that opener. Maybe I was angry about the bills and thus in a bad frame of mind for her request anyway, but when she asked for permission to skip school tomorrow, I snapped a negative and refused, really, to listen to her reasoning.
She tried to tell me it was a half day, that they probably wouldn't do anything important in class, that we had let her stay home the half-day before Thanksgiving. I told her no again.
Today, she came home from school with the news that she had talked to all of her teachers, and they had confirmed that they truly weren't doing anything in school tomorrow; they gave her tomorrow's work too. She asked again to stay home, this time clearly prepared for more serious verbal battle.
Again, I told her no, explaining that since we let her skip school the last time, I have felt guilty, that we had made the wrong choice, that it was not her place to judge whether a school day would or would not be productive, but that as a student going to school was her job, and she had to go.
She told me she likes to argue; I told her I hate to argue.

Then I got a phone call from Jonah's teacher. He and another student turned in reading homework that was exactly the same. She wanted me to talk to him and find out what happened. At first, he didn't admit to anything. Then he told me that he had finished his homework, set it to the side, and the other student began to copy it. I asked Jonah if the other student asked to copy it, and he said no. Then I asked him if he had known the student was copying it, and he said yes.
He didn't believe me when I told him that letting someone copy his paper is cheating too. There was a lot of silence from Jonah; that's how he processes his anger or frustration or sorrow. He doesn't show any emotion at all, just shuts down.

So now, Jonah still won't really talk to me, and I'm not sure he believes that he did wrong. Lauren will be going to school tomorrow, but I don't feel confident that she buys my reasoning. I'm worried that she's unconvinced that attending class is important, whether she thinks it is or not, whether she likes the teacher or not.
I know I did the right thing, so I'm not sure why I still feel doubtful about this whole enterprise.