18 years ago - Cassandra Cain is born, the daughter of David Cain and Sandra Wu-san. She is part of experiment by David Cain to create the perfect assassin, the League of Assassin's fabled "one who is all". She is brought up without language.
3 years ago - 15-year-old Cassandra Cain runs away after committing her first kill. She finds her way to Gotham during the No Man's Land quake, where she stops Victor Zsasz from killing Alfred Pennyworth. Her father David Cain battles Bruce Wayne to get her back, but retreats after she says her first work, "stop". She quickly adopts the role of Batgirl, accepting training from Barbara Gordon.
2 years ago - 16-year-old Cassandra is first confronted by Sandra Wu-san. She is told that they will battle to the death. When they meet again Cassandra defeats and spares her, and discovers that she is her mother. She defeats her father David Cain while he is framing Bruce Wayne for murder, leading him to turn himself in.
1 year ago - 17-year-old Cassandra Cain leaves Gotham for Bludhaven to assist Dick Grayson. She is given Katana's sword, and takes on her new Silhouette identity.
now - 18-year-old Cassandra Cain agrees to pass on the Batgirl identity to Stephanie Brown, and to help Barbara Gordon train her. She becomes a part-time member of the Birds of Prey.
Cassandra was awesome. The very first Batgirl to headline her own ongoing series and a completely original character, she starred in her own comic for over a decade before she was unceremoniously wiped from continuity.
Her story is fantastic, and there's very little we need to do to change it, but we did alter some elements later on. In the comics, she becomes a part of the Batman incorporated arc, taking up the name Black Bat, operating out of Hong Kong. It's a decent idea for the next step in her journey, but we like the character too much to pack her off to the other side of the world. Instead, we had he move to Bludhaven. At a time when Dick Grayson is leading the Titans offworld and then leading a new Watchtower, she would be an invaluable asset in his protection of his city. We also altered her name to something a little more deliberately ninja-ish, and gave her the enchanted sword of Katana. the end result is a character more in keeping with the original concept for Cassandra.
That's a pretty specific question!
The idea that Shiva is Cassandra Cain’s mother is introduced in Batgirl Vol 1 # 65, and was carried out through the two final story arcs of the series, culminating in issue #73, the final issue of the series. The question as to whether Shiva is actually her mother is deliberately left unanswered through both arcs so you mostly have flashback images from other characters memories, recalling moments when Cain and Shiva were together. It isn’t until the final issue that you actually hear the truth from Shiva herself. In flashback, she tells her story, and yes, the moment of conception is depicted... It's page 13, which looks like this. It’s drawn by Pop Mhan, an artist I remember primarily for his work on the Dark Horse series Spy Boy.
I honestly completely forgot this was even in here. I’ve owned this series for years, but this actual issue is really centered around the fight between Cassandra and Shiva. It’s depicted as their final battle and the culmination of Cassandra’s story. The preceding two story arcs had been leaning so heavily on the premise that Cassandra MIGHT be Shiva’s daughter that the final reveal is almost a foregone conclusion, so it doesn’t really stick in your mind.
Also, it’s worth pointing out that this issue is just generally terrible. This was an awful time pretty much across the board for DC; virtually every book was being forced to end all of its stories to make room for the forthcoming Infinite Crisis. Even the books that survived suffered a One Year Later time jump, and I can’t think of a single character that benefited from it. Batgirl was just flat-out canceled after this, and Cassandra herself was never depicted as Batgirl again, despite her being by far one of my favorite versions of the character. The whole issue is forced, rushed, and just generally unsatisfying.
Still, this series is fantastic. It happens sometimes that these things end with a whimper.