She is the daughter of the late actor Vinod Mehra from his third and last wife Kiran. She was less than two years old when her father died in October 1990. Since then she was brought up in Kenya with her brother Rohan by her maternal grandparents. Soniya went to school at The Mombasa Academy in Mombasa, Kenya and completed her education in London. She began her training in acting at the age of eight in school where she earned the Gold Medal with an Honours at The London Academy of Music and Dramatic Arts Acting Examinations. She also took a short course at The Arts Educational Schools of London. When she was 17, she moved to Bombay in and joined Anupam Kher?s ?Actor Prepares? for a 3 month course.
She made her acting debut in Victoria No. 203, a remake of the 1972 classic and released on 31 August 2007. She is also attached to star in UTVs Bombay High. After the release of Victoria 203 which was a commercial flop, Soniya took a long gap of three years and she is now attempting to make her comeback in 2010 with the film "Basra (film)" starring Abhay Deol and directed by Navdeep Singh. She is looking forward for more work in bollywood.