You entitled b****

Ask the child, then ask the nanny to explain the note to you. Do the listening, let her do the talking, don't preempt her by asking if she is feeling ok and needs time off. Make it all on her to explain. Then triangulate with what your child said and make your judgement.

It's not OK to write this to a 5 yo (if it was written to him), to me it would be a big deal, no matter how loud he is. Kindness is not optional, that note is very very rude.

I don't know about being rude. As a parent I would appreciate nanny teaching my kid to use soft voice inside. Kids are allowed anything these days, would not be OK with me. But - writing a note, to WHO? Maybe the kids done it and drove the nanny crazy for real, and now she is writing the notes to the world in general? Or maybe they were mailing notes to each other - we used to play a game like that, and one of the kids asked another to shut up? lol

I'm a mom and I've definitely told my kids to be quiet -- in a tone too. I'd appreciate that she was venting to the note.

Kids are tough and can drive you crazy. Spend weeks with them yourself with NO help and see what you say or are tempted to say.