Just a way to vent I guess. There are some goods minds on this board. Knowledge is power.
I’m more concerned for your daughter with that wacky 5th grader on the prawl. That note was violent. If the older sister of the accuser goes to your daugher’s church - does that 5th grader go there, also?
If I understand this right, seems like jealousy of your daughter and the accuser’s older sister’s friendship.
I agree with another poster here - say nothing but seek legal counsel. Most have free consultation - the problem is getting the right one. I think telling your son and daughter not to say anything for now is wise. The less said the better about your plans, etc. Does your wife teach at that school?