Aradhana (1969)

Arun meets Vandana during a vacation and very soon they secretly get married. Arun is an Air Force pilot and dies in a crash, leaving pregnant Vandana heartbroken--and unable to prove that she is a married mother-to-be. As her marriage was never formalized she decides not to keep the child, and her own father dies around this time. She gives birth to her son, Suraj, and when a wealthy couple adopts him, she decides to be the nanny. All goes well until Shyam, a relative, starts to eye her, and one day he tries to molest her. Suraj stabs him, and she takes the blame and goes to jail for it. Years later when she is released from jail, the jailer takes her to his house to take care of her daughter Renu. Renu starts bonding well with Vandana and introduces her to her lover--who is none other than Suraj. The moment she sees him, she knows he is her son because he is his father's exact replica. But she decides not to reveal this truth that might embarrass Suraj.