Choi was born in Vancouver, British Columbia, Canada. She moved with her family to Hong Kong a few years later. She was educated at a number of institutions. She is fluent in Cantonese, English, and Mandarin.
After graduating from Rosaryhill School, where many other would-be pop stars had attended, she started working full-time as a model in Hong Kong. She was scouted by Emperor Entertainment Group (EEG), and was then linked with Gillian Chung to form the Cantopop group Twins.