I guessed, since there are a total of four formal portraits of her, that she must have been an éminence grise and a good friend. How did we ever answer questions before there was Google? Several gems turned up, and this one, from the Poughkeepsie NY-Eagle, December 9, 1936, shows Dr. Caul deserves not to be forgotten by Puerto Rico. This is from the :
NEW YORK. Dec. 8 - Dr. Martha F. Caul, Brooklyn Physician died last night at the age of 68.
Dr. Caul lived for many years in Puerto Rico and in the hurricane of 1928 [?] headed a Red Cross delegation in relief work. She also led a $2,000,000 relief fund drive for victims of the disaster.
She attended public schools in Buffalo and was graduated from the Buffalo Medical college. Funeral services will be at her home tomorrow and burial will be at Brant Center [?], N.Y. her birthplace
She also turns up in Ancestry.com, where the image of a 1916 passport application reveals that she was born on May 2, 1869, and her profession is listed as farmer. She's there in the 1920 census as well, where, as a widow, her role in the family is head-of-household, and the industry in which she works is a finca de toronjes - she had a grapefruit farm! Here's another extraordinary tidbit about her life from the Emporia (Kansas) Daily Gazette of May 5, 1933:
Dr. Martha F. Caul, of Brooklyn, one of the best known women physicians (she witnessed the operation on McKinley when surgeons tried to save him from the assassin's lead) is said to have been the first women to own and drive a motor car in New York State. Barney Oldfield taught her.
McKinley was assassinated, in 1901, in Buffalo New York, so that excitement took place before she came to Puerto Rico.
My grandparents kept wonderful company: Dr. Martha F. Caul must have been an intrepid woman indeed, start-to-premature-finish.