A surgeon in the Colonial Service, Barry was stationed in countries including South Africa, Canada and Mauritius and also served in the Crimean War. It is believed that she gained a reputation for having a flirtatious manner, and became known for sexual peccadilloes involving fellow officer’s wives and the officers themselves. She is also said to have fought a duel over a woman in 1819.

It is all the more remarkable that Barry held the disguise of being a man for more than 50 years, as she would have maintained a smooth face when abroad while colleagues would have typically grown facial hair.

Barry was described as being 5ft tall, with a pale face, high cheekbones, sandy curls - dyed red in later life - a long nose and blue eyes. Her hands were small and delicate. Many of her acquaintances later reported that they had suspicions about her true sex, some believing her to be a hermaphrodite.

While in Trinidad, Barry contracted yellow fever and it is believed that her sex was discovered as a result. However, reports suggest that she managed to persuaded the doctor who made the discovery not to unveil her secret.