My mom let my 3yo nephew use my painting supplies and ruined most of what they used

The colors got mixed in moat of the containers, 5 of them were left open and dried out, the brushes weren't washed off. Worst of all she let him use a painting that was already mostly finished to paint on completely ruining it.

I just bought the paint and spent almost 2 days on the painting and I'm pretty pissed off that both were ruined.