 Power was Director of Studies in History at Girton College, University of Cambridge (1913–21), Lecturer in Political Science at the London School of Economics (1921–24), and Reader of the University of London (1924–31).In 1910 she was awarded the Gilchrist research fellowship and studied at the University of Paris and the École des Chartes.From 1922 until her death in 1940 she lived in Mecklenburgh Square, on the fringes of Bloomsbury.