:-) yeah I’d been watching Game of Thrones a LOT back then. You could argue it's an Anna & Elsa situation as well, or Beezus & Ramona. It's an archetypal relationship.
Parallels upon parallels: Diana is smart but she’s incredibly athletic as a child, as we’ve all seen in the movie. I want to set up a sisterhood where both aspire to be like thier hero and mentor, but the younger sister is more like younger Diana, and the elder sister is wiser (despite mental health) like an adult Diana. Diana’s never had sisters like the Sandsmark girls, so she’s fascinated seeing herself reflected at both ages in different manners.
When [Donna] appears, she’s like Vanessa... in that she never excelled at the athletic challenges the Amazons put her thru. She excelled instead at spellcraft... but that’s a bigger thread. In any case, Donna’s appearance requires nearly all of Diana’s time and effort, and Vanessa is a bit heartbroken that she’s left behind and never realized the potential Diana saw in her. So she graduates to college, and Donna goes to the Titans. All the while, the audience is like, Vanessa and Donna would be best friends if they’d just had the time to develop their own friendship.
Anyway, College life messes with Vanessa, and one of Diana’s rogues figures out there’s a connection between Nessie and the Amazons. A year later, Silver Swan emerges and necessitates Cassie becoming the new Wonder Girl to protect Gateway.
What I haven’t figured out is why/how a villain that would deduce the connection to Amazons thru Vanessa wouldn’t also follow it to Cassandra and her mother. How do you preserve thier secret identities? Details bleh.
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Fixed it. I've already said how College messes with Vanessa, let's have her attend a Veronica Cale anti-Wonder Woman rally, like the hate speech rallies of Milo and Richard Spencer. She and other angry young men are kidnapped because the tech used to fuel the Swan cybertech runs on hatred. The boys all die in the process, but she persists because 1) she's crazy, and 2) she has legitimate intimate reasons. It's not that the villains know she's a Wonder Woman relation, but that she's a unique boiling point of hatred. It makes her victimization about HER and not Diana, that the kidnapping occurs because of Vanessa's mental health weakness.
"Silver Swan" becomes a commentary on the strength and corruption of hate speech on fragile worldviews, and how screaming hate is dangerous.