The fleece is as white as snow, meaning the lambs wool
Note to Mary had a little lamb on recorder: B A G A BBB AAA BBB B A G A BBB AA B A G
You just said it, it is "Mary Had a Little Lamb."
According to the Oxford Dictionary of Nursery Rhymes, Mary Had A Little Lamb was written by Sarah Hale in 1830.
It seems to me that she was a shepherd. That's my best guess. That is, according to the Nursery Rhymes video I have. I'm not sure if Kindergarteners even get those any more. It never actually never...