Thanks, Lyle ! The tune on the website you mentioned: www.redhotjazz.com/Songs/chubb/horsey.ram is the one my mum sings. I wonder if this is the one CapriUni knows, too?

Here is the verse(taken from that recording):

Now Reuben's wife, she was so silly,

She never wore her hat.

And though the sun was shining,

She didn't give a darn about that.

You could seen them driving in their buggy every day,

And Reuben, he would lean right back

And hear his wifey say:

"Horsey, keep your tail up ..." etc.

- Jeanie