Philippa G. Fawcett, educationist, was the eldest child of Professor Henry Fawcett and his wife, Millicent Garrett. She was educated at Clapham Middle School and Clapham High School in London and from 1885 to 1887 studied pure and applied mathematics at University College, London. Her outstanding results in algebra and geometry led to her being awarded a Cilchrist scholarship to study mathematics at Newnham College, University of Cambridge, a college for women that her mother had helped to found. After two years she graduated in 1890 as senior wrangler [i.e., first in the honours examination for the BA degree in mathematics]. During her student days she also took an interest in physics, attending the practicals conducted by J.J. Thompson, who was experimenting with the passage of electricity through gases and later discovered the electron. A scholarship enabled her to undertake research at Cambridge for a year, the results of which were published in a paper on the motion of a helical body in a liquid, published in the Quarterly Journal of Applied Mathematics. She was then appointed as a lecturer in mathematics at Newnham College. In 1894 she published a paper on "The electric strength of mixtures of hydrogen and nitrogen" in the Proceedings of the Royal Society of London.
In November 1899 Fawcett took a break from lecturing to travel for nine months, during which she visited India and Japan. Then, in July 1901, during the Anglo-Boer War (1899-1902), she accompanied her mother, who had been sent by the British government to South Africa to report on the British concentration camps for Boer civilians. As a result of her experience she applied for permission to return to South Africa to help set up an education system in the Transvaal Colony. When permission was granted she resigned her position at Newnham and in July 1902 took up an appointment as lecturer in mathematics at the Normal School in Johannesburg, where she trained mathematics teachers. The next year she was an examiner in mathematics for the BA degree, the survey certificate, and the first mining examination of the University of the Cape of Good Hope, and an examiner in coordinate geometry and dynamics for the MA degree of the same institution. She appears to have been transferred to Pretoria in 1904 to serve as private secretary to the acting director of education. However, the next year she returned to England to take up the post of principal assistant to the director of education of London County Council, a post she held until her retirement in 1934.
Fawcett was a modest and retiring person who was remembered by her students for her infectuous delight in what she was teaching.