She soon became a household name with her best-selling hit I Am Woman, for which she won a Grammy and turned her into a feminist icon.
The 1972 single was recently turned into a biopic, starring Tilda Cobham-Hervey as Reddy, which launched on the streaming service Stan, earlier this month.
She went on to have three number one hits and another dozen songs in the US top 40, and was regarded as the queen of 1970s pop.
Her other iconic tracks include Delta Dawn, Angie Baby, Leave Me Alone (Ruby Red Dress) and Ain’t No Way To Treat A Lady.