Polly, Put the * * * * * * * Kettle On

I have 2 questions.
1. How many times do we to have to tell Polly to put the kettle on?
2. What kind of nursery rhyme is this?

The worst part is, is that this seems to be a semi-favorite of W's. Hopefully, just because there are more pictures on this page of his book than others. I can write a better rhyme than this. Seriously.

and I want to cry each and every time I have to read it. I try to jazz it up a bit but there are only so many ways you can change the expression in your voice as your reading. You try it.

Polly, put the kettle on
Polly, put the kettle on
Polly, put the kettle on
We'll all have tea.