If you're referring to Mary, daughter of Col James and Mary (Haley) FitzG, she d unmarried and is buried with her FitzGibbon grandparents in Dublin, if I remember rightly.
Charles Thomas and Agnes Dunbar Moodie FitzG had seven children, James Gerald, Geraldine, Eliza Dunbar, Charlotte Alice, Katie, John Wedderburn Dunbar and William Winder.After Charles' death Agnes remarried, to Col. Brown Chamberlain, and they had a daughter Agnes Gertrude Mary.
William Wilder dunm.
James Gerald m. Elizabeth Anna Breakenridge and they had a daughter, Mary.
All of the above is (or, perhaps, was) on the internet, because I made no trips to uncover more. They are distant to me as well.
There three books I know of which discuss Col. James.Mary Agnes FitzGibbon wrote, "A Veteran of 1812, The Life of James FitzGibbon." (Mary Agnes was a direct descendant of the Col.)The second, written some 90 years later, is "James FitzGibbon, Defender of Upper Canada," by Ruth Mckenzie; the third is, "The Green Tiger," by Enid L. Mallory. The last one is the least of them.
I just checked, and all three are available on Advanced Book Exchange (Google: abe)The postage will be more than the cost of the books.