Aldrich-Blake trained at the newly established London School of Medicine for Women from 1887, graduating in 1892 with a first-class degree in medicine and obstetrics. Two years later she obtained her Doctor of Medicine (MD) from London, and it was in 1895 that she became the first woman in Britain to be awarded the degree of Master of Surgery.
Aldrich-Blake held a number of notable positions in medical practice. These included her appointment as the first female anaesthetist at the Royal Free Hospital in 1895, which served as the teaching hospital for the London School of Medicine for Women.
From 1914 she was appointed Dean of the London School, which had by then become part of the University of London (and later of University College London). Her Deanship saw a doubling of students during the First World War, as increasing numbers of women sought medical training.