Over time, her connections to Batman and the rest of the family grew along with her ability to speak, to the point that Bruce formally adopted her as his daughter. As a member of the Wayne family, she has recently begun increasing involvement in activism for disabled people and ESL speakers in and around Gotham; as a heroine, she has done several stints under other aliases to act as an observer for Batman and Oracle. During both of these periods in her life, she has developed bonds with several individuals formerly counted among Gotham's rogues, including Clayface. While she was operating in these roles, the vigilante Spoiler—who had been acting as Robin for some months—took on the role of Batgirl.

Being close friends under each of their identities, the two Batgirls eventually opted to share the title while working under the original Batgirl, and have taken to protecting Gotham with supervision and coordination by Oracle.

Lilit Rising
Spoiler Alert! The following contains plot details for the events of lilit rising
Accompanying Bruce to Japan when he tried to reconnect with the daughter of his instructor in kenjutsu, Cass met Saotome Ranma and felt an immediate bond with the Jusenkyō-enchanted youth that went beyond her growing questions about her own gender identity. Discovering that Ranma was Bruce's child by birth, she reluctantly took part in the search for Ranma after he ran away in response. To her frustration, a pause at a local restaurant to get something to eat led her to meet Ranma in disguise, eventually sharing her feelings and her story with him. Her suspicions about the nature of Ranma's disguise as the waitress Haitao helped affirm that the enchantment had granted more than just the change between male and female, and gave her an opportunity to relate what she had been thinking about who she wanted to be.

When Ranma came to terms with who she was in terms of both gender and parentage, Cass offered her support and familial affection, after a brief bit of anxiety over nearness to Tendō Kasumi, a very pretty girl with a name that Cass herself had used as an alias. On returning to Gotham, she began exploring resources about gender and sexuality, and then outed herself to her family and closest friends—starting with Steph, who she also took the opportunity to ask out on a date.

By the time Ranma came to visit Gotham, Cass realized with a bit of panic that she hadn't actually verified that Steph knew about her newest sibling, and had to intervene when her fellow Batgirl mistakenly attacked Ranma at Wayne Manor. Settling matters, she took part in a shopping expedition to help Ranma add to her wardrobe. Ultimately, the passage into the new year saw her comfortably in the company of her girlfriend, her little sibling, and the rest of the loving family she had found.

• Martial Arts: Cass was trained from birth in a variety of world martial arts emphasising lethal strikes. However, she refuses to use actual killing techniques, limiting herself to temporary injuries at the most. In spite of this code, Batman has cited her as the deadliest fighter on the team, due to her inventiveness, depth of skill, and ability to predict opponents' movements by observing minute muscle movements.
• Multilingualism: Cass's native language is 'body language'; as with other users of the 'language of combat', she is skilled at communicating her intent to others through aggressive movements even without them training in this system. She comprehends English, Cantonese, Mandarin Chinese, and Japanese with a moderate degree of fluency, but has a limited ability to speak and read in these languages.