I copied these reference book titles off the Internet, if you check with a library for these books, they may contain a picture of Lady "May" Francis Hope. In Pennsylvania there is an inter-library loan program, Access-PA, where one can borrow books from any library in the state.
Biography & Genealogy Master Index (BGMI) 1265306 Yohe, May 1869?-1938 Biography Index. A cumulative index to biographical material in books and magazines. Volume 3: September, 1952-August, 1955. New York: H.W. Wilson Co., 1956. (BioIn 3) Notable Names in the American Theatre. Clifton, NJ: James T. White & Co., 1976. Earlier edition published as "The Biographical Encyclopaedia and Who's Who of the American Theatre." "Necrology" section begins on page 343. This book often alphabetizes by titles of address, e.g.: Dr.,Mrs., and Sir. (NotNAT B) Who Was Who on Screen. Third edition. By Evelyn Mack Truitt. New York: R.R. Bowker Co., 1983. (WhScrn 83) Who Was Who in the Theatre: 1912-1976. A biographical dictionary of actors, actresses, directors, playwrights, and producers of the English-speaking theatre. Compiled from "Who's Who in the Theatre," Volumes 1-15 (1912-1972). Four volumes. Gale Composite Biographical Dictionary Series, Number 3. Detroit: Gale Research, 1978. (WhThe) ========== 1265307 Yohe, May, Lady Francis Hope 1869?-1938 Index to Women of the World from Ancient to Modern Times. Biographies and portraits. By Norma Olin Ireland. Westwood, MA: F.W. Faxon Co., 1970. (InWom) ============ Patch, S.S. (1976) Blue Mystery: The Story of the Hope Diamond. Smithsonian Inst. Press, Washington, DC. (I have a scan of her picture that appears in this book, which I can e-mail any interested party.) ========= I also saw a listing for their picture together in a newspaper archive kept at a university library in Philadelphia, I had a crash of sorts and lost the url for that listing. I think it was at the Temple University library. I believe newspaper archives are your best source, because they were newsmakers of their day.