Agnes Herbert was once resident in the Isle of Man, seemingly from childhood though nothing turns up in the census records. She appears to have lived either in Port Erin or nearby. Her book, The Isle of Man, appeared in 1909 and can be downloaded from here:
Along with her cousin, she was a big game hunter, producing accounts of her trips to Somaliland, Alaska, and the Caucasus mountains.
I have the following references to her background but do not have access to the Czech or Capstick ones which may include details of her time in the Island as well as her links to it.
Any further information would be welcome.
Jones, Timothy S. “Agnes Herbert (circa 1880–7 Feb 1960).” British Travel Writers, 1876–1909. Eds. Barbara Brothers and Julia Gergits. Dictionary of Literary Biography. Detroit: Gale Research, 1997. 178–80.
Czech, Kenneth P. “Agnes Herbert, the Penultimate Diana.” With Rifle and Petticoat: Women as Big Game Hunter. New York: Derrydale Press, 2002. 67–84.
Capstick, Fiona C. “The Herbert Cousins—Somaliland Safari.” The Diana Files: The Huntress-Traveller Through History. Johannesburg: Rowland Ward Publications, 2004. 179–87.