Next, Jo Beth began peeing on the floor.

It wasn't that she couldn't hold her urine, exactly.  After all,
she'd had a Birch procedure--which makes it easier to hold your
urine than to let it go.  The problem was, she now couldn't hold
it long enough between recesses to (take a deep breath, now):

Make it to the bathroom downstairs and wait until all of the
first floor teachers who had gotten there first were finished!

She had three simple choices:  
1.  Pee down her leg.
2.  Wear a diaper.
3.  Pee in a container after the students left the room,
and then pour it down the sink and wash out the container,
breaking all health codes and probably the law.

So, that's what she did, with much use after of Lysol and bleach.
She Can't Make It If She Tries

Where Jo Beth leaks.
Study Questions:
How could she be so utterly filthy?
What if a child had gotten ill from her
nasty, nasty pee-pee germs?
Sometimes, Jo Beth
didn't make it to the sink.
Oh, come on.  For cryin'
out loud, it's only pee.  
Not as germy as that other
stuff, and more easily
cleaned.

You could eat off her sink.