My mother, born in the 1940s in Victoria British Columbia (to a first Canadian generation English father and second generation Irish mother), told me a story with accompanying song that she says was sung to her by her mother. My sister and I have sung the lullaby to our children.
Here are the lyrics:
Mother Moon in her gown of white
Peeking over the garden at night
In at the window comes to peep
To see if her children are fast asleep
Her gown is a garden stretching far
Every flower's a shining star
She will not pick them, don't you see?
She's saving them all for you and me
The story to go with the song was of a mother and father who's toddler was washed away in a flash flood and presumed dead. Years later the mother hears a young girl singing the lullaby while pushing a baby in a pram in a park. Because the mother made up the song, she instantly knew that the girl was her daughter. The girl was from an orphanage (pushing another baby from the orphanage in the carriage). They were reunited because of the song.
My mother maintains that the story was true. I find no mention of the story or the lullaby on the internet.