Aston was born in Purley, Surrey, and came from a theatrical family. Her father was a comedian, while her mother had been a dancer before becoming her husband's straight man. They also performed as acrobats. Her brother Lance performed at the 1980 Eurovision Song Contest with the band Prima Donna. Aston herself trained as a dancer, singer and actress at the Italia Conti School of Speech and Drama and performed on stage many times in her teens, mainly as a dancer. She was named "Miss Purley" in 1978 and competed in the subsequent Miss England contest, in which she was unplaced. The interval act at the televised Miss England 1978 competition was the group Co-Co, who had just been selected to represent Britain in the Eurovision Song Contest 1978 and featured Cheryl Baker in the line-up.