Winstone was born in Camden, north London. She is the daughter of actor Ray Winstone and his wife Elaine McCausland. She has two sisters, Lois (born 1982), the eldest, who is a singer and sometime Actress, and a younger sister, Ellie (born 2001). Jaime grew up in Enfield, north London, where she occasionally attended Enfield County School, a local state school.
Winstone's credits include the films Bullet Boy (2004), Daddy's Girl, Kidulthood (both 2006) and Donkey Punch (2008), the television series Murder Investigation Team, Vincent (alongside her father), Totally Frank, Goldplated and Dead Set and a short film called Love Letters. She was cast in the BBC pilot Phoo Action, but a planned series was cancelled just as filming was about to start.
She made her catwalk modelling debut in 2008, for Vivienne Westwood and in February 2009 she appeared on the front cover of Arena.
Winstone sings backing vocals for her sister Lois' band. As an Actress she has appeared in the music video for The Streets' single "When You Wasn't Famous", The Twang's single "Two Lovers", and Hercules and Love Affair's single "Blind". In April 2009 she co-starred with then-boyfriend Alfie Allen in the music video for the Madness single Dust Devil.
The spring of 2010 also saw Winstone portray Anneli Alderton, one of five women murdered in Ipswich 2006, in the BBC drama Five Daughters. Alderton was the third girl to go missing in December 2006. In the summer of 2014 she filmed the lead role Lauren in Sky 1 comedy drama After Hours.