Everyone who knew Ruby Kane adored her. Sadie relates how her grandparents (Ruby's parents) keep a small shrine to her in the hall cupboard: "Mum's childhood artwork, her O-level results, her graduation picture from university, her favorite jewelry" (3.27). Smart and talented: it's no wonder Iskandar characterizes her as a "brilliant scientist" (15.110) and one his best students.
She's got both brains and beauty. While looking at a picture of her mom, Sadie reflects: "Mum was gorgeous, even in shorts and a tattered T-shirt. Her eyes were deep blue. Her blond hair was clipped back. Her skin was perfect" (3.28). Sadie both misses her mom and is a little envious of her looks. But then, are any teenagers happy with their looks?
Ruby's intelligence also helps her cut through illusions and deceptions (which is kind of ironic, given that she has communed with Isis). During the climactic binding of Set in Washington, D.C., Ruby's voice comes to Sadie, telling her to watch for her enemy. All along, the kids have been charging ahead under the assumption that their enemy was Set. But what if Set's not the enemy? It takes a sharp mind to see that there might be other layers of influence here.
Ruby also had the rare gift of divination, which according to Iskandar is "[o]ne of the most difficult forms of magic, and she was the first in centuries to possess it" (15.110). This isn't just a quirk or random plot point. Because Ruby was able to commune with Isis and see the future, she and Julius embarked on a path that would ultimately cost both of them their lives. But it came with the potential to save the world. Sound like a fair trade?
When the kids meet their parents in the Hall of Judgment at the end of the book, Ruby doesn't sound like she has any regrets. She misses getting to raise her kids, and she makes appropriately embarrassing remarks about how much they've grown up. She even asks whether they're dating yet.
Ever the scientist, Ruby reminds her children of the law of conservation: that energy and matter can't be created or destroyed, only changed. Ruby smiles and takes Julius's hand, saying: "And sometimes changed for the better" (41.81). It's been a long road full of sacrifices for Ruby, so we're happy that she at least gets to be with Julius and see her children again sometimes.