I don’t have kids so I can’t offer any specific advice there. But: in clinical research we use the acronym “ALCOA” to stress the importance of documentation.

A: attributable (clear that you wrote it)
L: legible
C: contemporaneous (written when it happened)
O: original (blue pen!)
A: accurate

I don’t think it would hurt to take some handwritten notes when something comes up that you think might be a problem later. Get one of those composition books that you can’t tear pages out of. Sign and date each entry. Cross out the rest of the line after your signature/date so nobody can say you added anything later. You can even take a photo after you write something (timestamps in photos are very hard to modify permanently).

Think of it as your lab notebook. That kind of evidence is spectacular in court. Just some paranoid advice from a paranoid nerd.

H: 35 W: 33
M: 11 T: 13

4/10/18: I discovered A and confronted ("BD1")
6/23/18: I moved out
8/31/18: MC ends ("BD2")