Famous for her educational crusades, the left-wing Labour MP and former education minister campaigned tenaciously to tighten up the legislation surrounding childminders and to ensure pregnant schoolgirls received daytime education.
Although she had no children of her own, Joan Lestor ran a children's home in her own house. She took six youngsters into her home and adopted two of them.
Her first job was as a nursery school teacher but she then joined the Labour party and was elected to Parliament in 1966.
She was first elected MP for Eton and Slough and served in Harold Wilson's and James Callaghan's governments as an education junior minister.
Sexual and physical abuse, neglect, missing children, HIV-positive babies, and boys and girls forced into prostitution all attracted her attention and energies.
She was Labour's first spokesman on women's rights and welfare and she championed many of the causes of women and children. She was also a fierce campaigner on racial issues and became vice-president of the Anti-Apartheid Movement.
She became a junior minister in the Foreign Office in 1974 and was then moved sideways into the Department of Education and Science. Her latter post did not last long - she resigned in protest over the education cuts in 1976.
Joan Lestor lost her seat in 1983 when her constituency was redistributed, but after four years she won the safe Labour seat of Eccles, where she stayed for the rest of her Commons career.
She retired from the shadow Cabinet in 1996, after motor neurone disease was diagnosed. Lady Lestor was made a life peer in John Major's all-party list last year.