The version in Sing Out! is quite different:

STEP IT OUT NANCY
(Robin Williams and Jerome Clark)

Step it out Nancy, purty darlin'
Step it out Nancy, if you can
Step it out Nancy, purty darlin'
Show your legs to the wealthy man

At Cheyenne in Wyoming
There's a maiden fine and fair
Oh, her eyes they shone like diamonds
She had long and golden hair
When the cattleman came a-riding
He came to her father's door
Mounted on a silk white pony
He came at the stroke of four
(Chorus)

I've come to court your daughter, Nancy
Of the golden hair
I have wealth and I have money
I have goods beyond compare
I will buy her silks and satins
And a gold ring for her hand
I will buy my love a mansion
She'll have servants to command
(Chorus)

Can't you see I love a cowboy
And I promised him my hand
I don't want your house and money
I don't want your goods and land
Nancy's father spoke up sharply
Said You'll do as you are told
You'll be married on the Sunday
You will wear the ring of gold
(Chorus)

The cattleman spoke with fury
Said You will not have that man
And he rode from town in anger
With a rifle in his hand
He came back from Colorado
On his pony was a sack
Deep red with the blood of the cowboy
A-slung across the back
(Chorus)

Pury Nancy cried in anguish
She wept and tore her hair
She slipped into her father's room
And found a pistol lying there
On the Sunday came the wedding
The townsfolk gathered at noon
They saw Nancy pull the pistol
And shoot down that wealthy groom
(Chorus)

Nancy said I am not sorry
When the jury heard the tale
Though he rots beneath the ground
And I shall rot in jail
There in the crowded courtroom
Twelve good men took their stand
Said We will not hold you, Nancy
For killing that wealthy man
(Chorus)

Music and lyrics by Robin Williams and Jerome Clark
© 1979 Love Breeze Music

Notes from Sing Out!: "Women are always getting killed in murder ballads," Robin Williams declares, but he's decided that it's a tradition worth breaking. "Step It Out Nancy" is what Linda Williams gleefully calls "an affirmative action murder ballad."
Robin and Linda's original songs are rooted in the mountain music of the south. "We try to delve into every subject of country music," Robin says, "and of course murder ballads are among the most popular." Robin and Jerome Clark wrote the lyrics for "Step It Out Nancy" after listening to the Dayhills sing "Step It Out Mary," a suicide ballad of Irish origin (on Mom's Favorites, Biscuit City 1308). Mary is a young woman in love with a sailor, but her father orders her to marry for wealth. On her wedding day, Mary and the sailor drown themselves. In "Step It Out Nancy," the story moves to the American west and the heroine chooses a different fate.
Robin and Linda are known for their harmony singing, and we've included a harmony line here. To hear their variations on this basic harmony, listen to "Step It Out Nancy" on Dixie Highway Sign (JAO31, June Appal Records, Box 743, Whitesburg KY 41858).

Source: Sing Out! The Folk Song Magazine, Volume 27, No. 5 (Sept/Oct 1979), page 16

This transcription doesn't match the Robin and Linda Williams recording. I wonder where it came from.

Here's the Robin and Linda Williams recording: https://www.youtube.com/watch?v=aWdmUqb6Ojc

Holly Near recording: https://www.youtube.com/watch?v=88lKY6jeiDo