I hope you receive this message. According to the "Natchez Area Family History Book," published in 2004 by Turner Publishing Company, Mrs. Catherine Typer Junkin-Mahan was born in Kentucky on August 3, 1780. She moved to Natchez around 1794. She married Thomas Tyler in October of that year. By 1805, she was a widow with three children: Sally, Mary "Polly,' and Margaret.
On April 7, 1808, Catherine Tyler married William Junkin. They had two children: Eliza Jane and Joseph R. William died a few years later. On July 5, 1813, Catherine married Arthur Mahan. He was born in Ireland in 1772. This marriage lasted 8 years. Arthur died on November 9, 1821.
According to the Adams County Sexton Records, Catherine died of old age on August 10, 1851. She was 71 years old. Her estate was probated on October 11, 1851; two heirs were named Eliza J. (Junkin) Paine and Margaret (Tyler) Smith. Catherine is buried in the Old Catholic Section of the Natchez City Cemetery next to her third husband, Arthur Mahan.
The biographical sketch was submitted by Ginga Hathaway.
The Natchez history book was assembled by the Natchez Historical Society.
You can check the Natchez City Cemetery site to find information about Catherine and Arthur's burial site.

Ironically, you mention that a possible relative of Arthur Mahan was a man named Fagen and that he went to work at James Junkin's shop as a mechanic and wagonmaster. James Junkin arrived in Natchez in December 1851. He was an elder brother of my great-grandfather, David Junkin. They lived in Larne, Ireland. In 1874, David and his very large family, moved to Natchez. Prior to that time, David's eldest son, Thomas James, came to Natchez and worked at James' blacksmith shop on Main Street.

Our family has tried to connect James Junkin to 'our' Junkin ancestors but without success Maybe Mahan, Fagan and the Junkins' were associated back in Ireland.

I hope this information is helpful to you. Please contact me if I may be of further assistance.