Interesting question. I had a look at Wikipedia and quickly dispelled the thought: Sullivan died in 1936. Keller went on to write several books after her death

Interesting question. I had a look at Wikipedia and quickly dispelled the thought: Sullivan died in 1936. Keller went on to write several books after her death: Let us have faith (1940), Doubleday, & Doran & co., inc. Teacher: Anne Sullivan Macy: a tribute by the foster-child of her mind. (1955), Doubleday (publisher) The open door (1957), Doubleday, 140pp The faith of Helen Keller (1967) Helen Keller: her socialist years, writings and speeches (1967)