Reddy died in Los Angeles on Tuesday, her family said in a Facebook statement.
Her children Traci Donat and Jordan Sommers have described her as “a wonderful mother, a wonderful grandmother and a really great wife”.
“Our hearts are broken. But we take comfort in knowing that his voice will live on forever. “
Reddy had a string of pop and rock hits in the 1970s, but he is best known for the 1972 anthem I Am Woman – a catchy song that rose to prominence in the women’s liberation movement.
It sold over a million copies and became a defining song of second wave feminism.