Since her version was published in 1973, it's definitely under copyright. She did not list her source, but back in 2021 I went searching. At that time I found and posted the Jeremiah Curtin version here titled "The Blood-Drawing Ghost." It's safely in Public Domain
When you are preparing to tell a story, we aren't limited to one version. The late Chuck Larkin also loved the story. His daughter has done us the service of keeping his website alive. It includes a page of Stories "adapted for telling by Chuck Larkin." There are many Christmas Stories, Fish Stories (tall tale telling was his specialization), Halloween Stories, and much more about Tall Tale Telling, as well as a version of "The Marriage of Sir Gawain and Dame Ragnell" and a Celtic tale about Fianna Warriors called "The Hunt."
Here is his version of "Mary Culhaine." Stick around after it for a funny and an equally favorite true tale about when I told the story.
I promised to tell a story about me telling the story. With spooky storytelling it's best to warn your audience the stories will get spookier as your program proceeds. Once I was hired to tell at a Halloween party with a variety of ages and activities. I was parked with the kids, mainly girls on the edge of becoming teenagers. With them was a little boy who kept asking me if I had any stories about Darth Vader (he pronounced it Dahth Vayda). Finally to the relief of the older kids he moved on to another activity. I began "Mary Culhane" and was in far enough when he returned. He was quickly brought up to where we were in the story and I proceeded. We had just gotten to the point where the three young men have their throats slit when an elderly woman cut through the room. I was sure she didn't consider the story appropriate for his age. She was long gone by the time the story ended and the little guy piped up with "That woulda been a lot sca'wier (scarier) if it had been about Dahth Vayda!"