After graduation, she worked in acute medicine in the UK and then went on to be awarded a Japanese MEXT scholarship,[5] which allowed her to further her studies in Tokyo.

With her training in aviation medicine, she was the CEO of West Africa's first air-operated emergency medical services in Lagos, Nigeria; Flying Doctors Nigeria Ltd.[7] She is a member of the American College of Emergency Physicians, and was listed among the 2013 Young Global leaders by the World Economic Forum.

[18] In 2019, she founded The Flying Doctors Healthcare Investment Company,[19] which operates air ambulance services and logistics.

It is involved in hospital construction, diagnostics and equipment, health facility management, and pharmaceutical retail.

[20][21][19][22] At the height of the COVID-19 pandemic in Nigeria, Brown and her HealthCa team launched a COVID-19 mobile testing booth, which reduced the need for personal protective equipment.