Ornithologist, who was one of the founders of the Scottish Ornithologists' Club. Tramped around most parts of Scotland studying birds. She and Evelyn Baxter made almost frequent visits to the Isle of May, and made meticulous records of the birdlife they saw there between 1907-1933. They included rare migrants and wind and weather data, making their data a unique record of that region. Baxter made broadcasts for schools on birds and their habitats.
Baxter and Rintoul wrote accounts of unusual bird behaviour in particular circumstances, such as during a partial eclipse of the sun in August 1914, and during the Zeppelin raid on Edinburgh in April 1916