Cassandra Cain
From Stephanie Brown
"Stephanie would say "Suck it up and deal!" Okay, Steph. For you."- Cassandra Cain, Batgirl #67
Oracle: "I worry you'll get hurt...or worse. I mean, poor Steph..."
Batgirl: "Don't. Talk. About. Her."
-Batgirl #67
Cassandra: Why does everyone I care about die?
Stephanie: Because...you care about everybody. And everybody dies.
-Batgirl #73
Relationship: Close friend, partner
Name: Cassandra Cain
Aliases: Batgirl, The-One-Who-Is-All
Height: 5'5
Weight: 110 lbs
Hair: Black
Eyes: green
Parents: Mother, Sandra Wu-San (alias "Lady Shiva), Father, David Cain
Siblings: Annalea (deceased), "The Mad Dog"
Summary: Though initially stand-offish, Cassandra Cain soon developed a very close friendship with Stephanie, even training her without Batman's permission. She was very affected by Stephanie's death, and has seen Stephanie twice in near death experiences.
Important events between Cassandra and Stephanie:
First team up (Batgirl 20)
The two girl's friendship is submitted when Stephanie revives the "Shadow Theif" using CPR after a tearful Cassandra has accidentally killed him and Stephanie promises not to tell Oracle. (Batgirl 21)
Stephanie takes on a Lady Shiva worshiper who wants to kill Cassandra while Batgirl is out of commission. She imagines Batgirl following her around, chiding her and egging her on, proving how much Stephanie admires Cass (Batgirl 26)
The two girls play "rooftop tag" and Cass repeatedly nerve strikes Steph to keep her out of trouble or to stop her from interfering with Cass's investigation of the Bruce Wayne case. This causes her to realize that a nerve strike was used on the victim, Ms. Fairchild. To celebrate, Cass and Steph play MORE rooftop tag. -(Batgirl 27)
Steph begins to train with Cass and they bond over father issues (Batgirl 28)
Cass trains Steph without Batman's permission, but admits she thinks Steph should stop crimefighting later that night. Steph goes away angrily. (Batgirl 38)
They team up as Batgirl and Robin (Batgirl 53)
Steph comes to see Cass to tell her she was fired as Robin and thanks Cass for her friendship (Batgirl 54)
When Batgirl nearly drowns, a ghostly version of Steph appears and convinced Cass to save herself (Batgirl 62)
After Batgirl is stabbed by "The Mad Dog" and dies, she meets up with the ghostly Stephanie once more. Cass is pulled away from Stephanie when Lady Shiva dumps Cassandra's body in the Lazarus Pit and she is ressurected (Batgirl 72-73)
More about Cassandra: Here