I keep thinking of this poem with the news stories from Pennsylvania. The girls were older...this is about a baby, but then, at 6 or 7 or 8 you  might still call your kid your "baby." This was set to music by Priscilla Herdman, or I never would have known about it. This was in some liner notes:

This poem, by Australian poet Henry Lawson (1867–1922), was inspired by a haunting dream related to him by a woman friend and was set to music by Priscilla Herdman in 1972. The tune came to her as she first read the poem at the home of dear friends who had lost their infant to illness on a sea voyage many years earlier.
On numerous occasions, parents grieving over the loss of young children or infants have told Herdman that this song has given them great comfort. She dedicates it with love to the Goldstein family, for their son Michael.

Here's the poem:

THE WATER LILY
Henry Lawson

A lonely young wife
In her dreaming discerns
A lily-decked pool
With a border of ferns,
And a beautiful child,
With butterfly wings,
Trips down to the edge of the water and sings:
“Come, mamma! Come!
Quick follow me —
Step out on the leaves of the water-lily!”

And the lonely young wife,
Her heart beating wild,
Cries, “Wait till I come,
Till I reach you, my child!”
But the beautiful child
With butterfly wings
Steps out on the leaves of the lily and sings:
“Come, mamma! Come!
Quick! Follow me!
And step on the leaves of the water-lily!”

And the wife in her dreaming
Steps out on the stream,
But the lily leaves sink
And she wakes from her dream.
Ah, the waking is sad,
For the tears that it brings,
And she knows ’tis her dead baby’s spirit that sings:
“Come, mamma! Come!
Quick! Follow me!
Step out on the leaves of the water-lily!”

(From ‘When I Was King’ - 1890)