Mary Louisa Boit (1874-1945)
"Isa" Mary Louisa Boit, of Newport, Rhode Island; died unmarried
She was born in Paris, where her father was an artist, and she was known (like her mother) as "Isa". She is immortalized in John Singer Sargent's famous painting on display at the Museum of Fine Arts in Boston: The Daughters of Edward Darley Boit (1882), where she is seen standing on the far left. She was very close to her younger sister, Julia. After the death of their eldest sister (Florence), the three remaining sisters lived predominantly in Paris up until the outbreak of World War II in 1939. When they returned to the States, Isa lived with her Julia at Newport. All of the sisters were unmarried which may be explained in the biography of their father.
