Gadd lived with her aunt and began to study dancing, working as a chorus girl in Brighton by the age of fourteen.
In 1924, she was cast in a production of Hassan by the powerful theatrical agent Basil Dean, after which she appeared in several musical comedies, then straight plays after becoming a member of a Shakespearian company at Stratford-on-Avon.
[3] In 1931, Gadd signed a contract with British International Pictures and spent two years making films for them.
In 1932, while working on the crime film White Face she began a tempestuous affair with her co-star Hugh Williams.
[5] Gadd married her first husband Guy Tooth, the youngest son of a family of Cork Street art dealers, in Westminster, in 1929.