Noise11 reports she had been in poor health since 2001.
Wikipedia notes Biddell started singing in 1965 as a session singer and her first live gig was as a backing singer for Dusty Springfield before performing with The Echoes, The Affair, and touring with The Strangers, The Executives, The La Di Das, the Daly-Wilson Big Band, Dudley Moore, Cilla Black and Buddy Rich.
She lived between Australia and the US with a 5 year contract with the MGM Grand Hotel in Las Vegas and was one the stars who opened the Sydney Opera House.
Biddell was a regular on TV variety shows including Midday, The Norman Gunston Show, The Ernie Sigley Show., The Graham Kennedy Show and had her own radio show, Kerrie Biddell and Friends on ABC radio. She also appeared on TV shows in L.A. including Midnight Special and The Merv Griffin Show.
She sang on hundreds of jingles and session recording and in 1982 she sang on the theme tune for Sons And Daughters.