The naval architect, was born at 12 Northumberland Terrace, Tynemouth, the only daughter and younger child of John Denham Christie (d. 1950), naval architect and shipbuilder, and chairman of Swan, Hunter, and Wigham Richardson Ltd from 1930 to 1939. Her brother became managing director of the Neptune shipyard in 1938.

In 1932 Susan entered Armstrong College of Durham University, in Newcastle upon Tyne, where she studied naval architecture and joined the North East Coast Institution of Engineers and Shipbuilders as a student member in October of that year, the first woman ever to be admitted.

After graduating BSc in 1936, the first woman to be awarded a degree in naval architecture, Susan joined the design office of Swan, Hunter, and Wigham Richardson at the Neptune yard on Tyneside. She was helped by the shortage of trained naval architects, caused by the reluctance of young men to embark on the profession during the slump.

During the Second World War Susan was a member of the design team for the battleship HMS Anson, launched in 1940, and the aircraft carrier HMS Albion. She also worked on the design of landing craft used by the allies to land troops in Normandy in June 1944. After the war, when Swan, Hunter, and Wigham Richardson returned to building passenger and cargo ships, she was a member of the team which designed the Leda, which carried passengers between Tyneside and Norway. Although she gave up her career as a naval architect on her marriage, for many years she wrote a humorous column in the company's in-house magazine The Shipyard under the pseudonym ‘Your Wallsend Correspondent’ She also played the Northumbrian small pipes and was a pupil of Tom Clough.