Maxwell became the Assistant Surgeon and Pathologist at the Royal Victoria Eye and Ear Hospital, Dublin in 1912 at age 25. She held this position until her retirement in 1957. She also served as honorary secretary of the British Medical Section of Ophthalmology. Maxwell attended some of those wounded during the Easter 1916 Rising in Dublin, working at a temporary hospital at 40 Merrion Square East. Her participation in these events was featured as part of the RCSI exhibition to mark the centenary of the 1916 Rising in 2016.