Sounds like it's time for the kids' curriculum to include the deveopment of girls and boys at this age. . . But, yeh, issue #1 is about private property and #2 about basic respect.

I'm glad the teacher and principal are on board for your kid.
GOOD JOB mothering. Growing up is as hard as growing old....
we've all got our work cut out for us, thank goodness for good friends and this support circle.