On 14 May 2021, Henryp cited Gathering Rushes in the Month of May, aka Underneath Her Apron. Link to " Gathering Rushes in the Month of May" posted above It's a song of merry May seduction. I'm adding some Mudcat links which could be added to that message.

One of the linked recordings in that post is A Wee Bird Cam' Tae My Apron · Jean Redpath · Abby Newton    https://www.youtube.com/watch?v=1uNGheGyvDo Casey sang this song on the 9 May 2022 Mudcat singaround

The lyrics of that Scottish variant are posted on Mudcat
A WEE BIRD CAM' TAE MY APRON


It fell on a morning, a morning in May
My faither's cows they a' went astray
I loukit me down and the heather was gay
And a burr stack tae my apron

also at Mudcat UNDERNEATH HER APRON

A pretty young girl all in the month of May,
She's gathering rushes just at the break of day,
But before she come home she had bore a little son,
And she rolled him underneath her aperon.

and

THE REAPING OF THE RUSHES GREEN

- As I walked out one morning, it being in the merry month of May,
Me and my two wild beagles, hoping to find some game to kill.
When I spied no one but Mary; she appeared to me like a virgin queen
She being at her daily labour at the reaping of her rushes green. -

is among lyrics posted at Mudcat discussion ADD: bonny little bunch of rushes/Gathering Rushes along with some related songs which don't mention the month of May