Maria Alzira Costa de Castro Cardoso Lemos was born in 1919 in the Portuguese capital of Lisbon.
Her mother, Maria Emília, was from Coimbra, and was the daughter of Afonso Costa, a lawyer, professor and politician, who had campaigned for Portugal to become a Republic and was one of the first Republican deputies during the monarchy and, subsequently, a government minister on several occasions.
Lemos wrote that she had spent all her childhood and adolescence in expectation and in hope for a revolution that would allow not only the return of freedom to Portugal but also allow her family to get together.
Her paternal grandfather, Elísio de Castro, was also a Republican, who played an active role with those who tried to overthrow the Estado Novo.
After losing her seat in the 1979 elections, Lemos became a member of the Advisory Council to the commission, representing the Socialist Party's women's organization, which she had helped found.
She also joined the Associação Portuguesa de Estudos sobre as Mulheres (Portuguese Association for the Study of Women - APEM).
In the last two years of her life, she supported the establishment of the Plataforma Portuguesa para os Direitos das Mulheres (Portuguese Platform for the Rights of Women), whose headquarters is named the Centro Maria Alzira Lemos.