It occurs to me, Cass is the only member of the Bat-clan who's heroism keeps her from her parents. Bruce does what he does trying to save his parents, Dick and Tim similarly. Barbara does what she does because of her father, inspired by him. Even Steph being Spoiler doesn't completely isolate her from her parents, especially not her mother.
But Cass has parents. Cain would take her back in a heart beat, and I beat even Shiva would be proud if Cass unleashed her fury on the world. She could have what Bruce, Tim, Dick, and (to some extent) Steph can never have, but she denies herself it, because the life she'd have lead would be that of a monster.
I'd never thought of it in that way, but to a large degree, Cass is kind of an anti-Batman in that she does what she does in spite of her parents.