Warning: Spoilers for Batgirl #1Cassandra Cain’s Batgirl is a valued member of the Bat-Family, and her commitment to Batman’s no-kill rule cements her as such. Since being introduced as an assassin, Cassandra has evolved into Batman’s perfect successor by following his practice of sparing lives. Her team-up with her assassin mother showcases how Cass fits into her father’s legacy, as Batgirl solidifies her devotion to Batman’s cause and proves that she is his daughter before she is Lady Shiva’s.

https://screenrant.com/batgirl-cassandra-cain-no-kill-rule-batman-father-daughter/