Francis was born at the former Charing Cross Hospital near Trafalgar Square, London. She is the eldest child of Frank Francis, a clerical officer with the Agricultural Society, and Marjorie (née Watling), an employment agent, who were married in 1944. She was raised in Streatham and was educated at the Lady Edridge Grammar School.
After training as a Dancer at the Royal Ballet Senior School from which she graduated in 1965, Francis performed with the Royal Ballet Touring Company in Britain, in the rest of Europe and the United States. She left the Royal Ballet in September 1969 to pursue an acting career.
She made the transfer to becoming an Actress through choreography, and performed with the Cheltenham Repertory Company between 1969 and 1970. She first appeared on television in 1971, before landing BBC Television drama roles including Kschessinska in Fall of Eagles and Lisa Colbert in Secret Army (1977–78).
She married the actor-writer Martin Thurley in Newton Abbot on 1 August 1977. They have two daughters Josephine (b. 1982) and Anna (b. 1988), and reside in Woodchurch, Kent.
In 1979 she starred in Dracula as Mina Van Helsing, opposite Laurence Olivier as Abraham Van Helsing.
She played the part of Susie Dean in Alan Plater's adaptation of the J. B. Priestley novel The Good Companions (1980) which was produced by Yorkshire Television. Writer John Sullivan met Francis and later created her best-known part, Penny Warrender in the 1980s BBC sitcom Just Good Friends.
She later played Nick's "old enough to be his mother" girlfriend in the sitcom My Family, and co-starred with Dennis Waterman as Sally Hardcastle in the 1989–1992 ITV drama series Stay Lucky.
In 2006, she guest starred in ITV prison drama Bad Girls as interior designer Catherine Earlham, who was sent to Larkhall on remand for embezzlement. The character played a key role in the exit storyline for fellow inmate Darlene Cake (Antonia Okonma). She is also a regular performer, and part of the original cast, of the touring play Seven Deadly Sins Four Deadly Sinners.
In 2009, she appeared as Julia in the second series of Mistresses on BBC1. In November 2009, she starred in the ITV drama Collision (2010). She also played a love interest for Rodney Blackstock in ITV soap opera Emmerdale, in 2015.
In April 2014, she made a guest appearance as a patient in the BBC hospital drama series Casualty.
