Alexander then attended Newnham College, Cambridge and studied natural science, initially focusing on physics.[4] She graduated with First-class honours in 1931, then received a PhD in geology for a thesis on Aymestry Limestone, under the supervision of Owen Thomas Jones.[2] She was a member of the Sedgwick Club, along with fellow female geologists, Dorothy Hill and Constance Richardson. Like all women graduates of Cambridge University at that time, she could not become a full member of the university until after equal rights were granted post 1945.[5]