When I was in grade school, many many years ago, I learned this song in class.
It was delightful then and evocative now of spring and innocence. I used the search device in your website, but I may have the words wrong.
It is very sweet and cheerful, and goes something like this:

Rosy Betsy, blue eyed Molly Molly
April is the time for folly folly
Blackbird's shout rings round about
And Jenny Wren is building in the willow

(I can't remember the line)
Put off the cloak you wear in town
Run on the highways up and down
And Jenny Wren is building in the Willow

Does it sound familiar? I asked my local library to research it and they came up with nothing, except that it sounded familiar. I am sure, very sure, it is one of the old music books we used in the early 60's. I can almost see it on the left side page, and a sweet black and white illustration.
Does anyone know this song? Is there more to it? Is there a title?
Thanks