(Batgirl I #62 (fb), 73 (fb), 65 (fb)) - Sandra gave birth to Cassandra Cain, and David Cain shot the midwife to keep their daughter’s existence a secret. Cain planned to raise Cassandra to be the perfect weapon, and her life had already started with an act of violence. After Cassandra Cain’s birth Sandra went into the wilderness and went on a vision quest. She came back reborn as Lady Shiva, a woman of both destruction and creation. David Cain and Lady Shiva both continued to be associated with the League of Assassins, but their interactions were tense after Cassandra's birth.

(Batgirl I #3 (fb), Batgirl Secret Files and Origins #1 (fb)) - Cain told Cassandra she was his adopted child, and she would never meet her biological parents, who'd given her up. Cain viewed her as his heir and trained her to be a killer. He went so far as to deny her verbal stimuli so she would only communicate with violence.

(Batgirl I #64 (fb)) - Cain took Cassandra along on a hit so she could watch him work, and Cassandra was astounded by his grace, gunning down a number of men while outnumbered and surrounded. Cain wasn’t afraid of Cassandra getting hurt accompanying him, but he was afraid that she would fail him and not live up to his expectations.

(Batgirl I #3 (fb), Batgirl Secret Files and Origins #1 (fb)) - At the age of nine Cain made Cassandra assassinate her first target, Faizul, but the incident deeply disturbed her. She rebelled against Cain and ran away from home.

(Batgirl I #1) - Cain swilled vodka and watched old training films of Cassandra Cain in which she maimed mercs.

(Batgirl I #65) - With Father’s Day coming Batgirl fell into a depressive move. She started wondering who her mother was, and asked Batman if he had any idea. They both suspected that her mother might be Lady Siva, and Batman remembered when he erred thinking Shiva was Jason Todd’s mother. Batman offered to help Batgirl in any way he could finding her mother, but she decided to embark on the quest by herself. Since she was in town Batgirl rang up Onyx, asking for a sparring session to blow off some steam. Onyx noted that her fighting style was more ruthless than usual, and said she felt light she was going a round with Lady Siva. Batgirl asked her if she thought Shiva might be her mother. Onyx only knew Shiva after when someone Batgirl’s age would have been born, but did remember that she had a complicated relationship with David Cain. She visited Cain in prison as Cassandra Cain, and he was pleased to really talk to her in the first time in years. She said she needed something, and Cain said he’d help her any way he could, but when she asked who her mother was he clammed up. She later broke into the prison as Batgirl and fought Cain, who said he wouldn’t reveal her mother’s identity even if she killed him because he’d made a promise. Cain had lost his edge in prison and batgirl had become more skilled over the years so she was able to dominate him and beat him to a pulp. Cain was pleased with her progress, but still wouldn’t talk, and he cracked a smile when she left a flower and a Father’s Day card on his battered body.