Bruce was born in Petersham and attended Francis Holland School in London.

[1] After finishing school, she earned a BSc from the University College of London.

In 1941, after the start of World War II, she enlisted in the Auxiliary Territorial Service, was commissioned and went on to serve in the Anti-Aircraft Command.

After the end of hostilities, she was appointed to the South African National Herbarium in Pretoria in 1946.

During her stay there she worked on a number of plant families, in particular the Labiatae and also on a revision of the genus Kniphofia.