Growing up in Hong Kong with six siblings, she often helped her parents run the family milk bar. Gladys' family is of Chaozhou heritage which she referenced in her inaugural address to Parliament after her election as MP. She studied at Belilios Public School. Liu attended Hong Kong Polytechnic University. She learnt to play the trombone and joined the Hong Kong Youth Symphony Orchestra. In 1985 Liu immigrated to Australia to study at La Trobe University. She started her career waiting tables at The Flower Drum Restaurant while studying. She studied Speech Pathology and is completely deaf in her left ear. She worked for the Victorian Education Department for 14 years providing support to students with speech impediments. With her father and husband she ran two restaurants and a pharmacy until her 2007 divorce. She has served as a government advisor for two Premiers of Victoria, served as Head of Business Development and Corporate Social Responsibility Advisor for Canaan Lawyers and President of Box Hill Chess Club. Her two children have attended Harvard and Oxford studying business.