Yeah, I think Sasha's got her fans partially because she's got the most mystery: why the scar? why the smouldering inscruitable looks at Nika? Why does Nika seem to recognise her? Why the earring? Why am I and my friends keeping tabs on him? There's so much more mystery than Bella: what happened to my sister? Nami has the earring and the dark secret, Nia's revealled her mystery, Mila's got ...something we don't know, but Sasha has the most undisclosed storyline ...well, other than SOnya, but there's no hint of a mystery there, we're just trying to get her away from her parent's control.
#1 Seemed like it was plausible when she first appeared, but the skin tone and lack of freckles made me realise quickly that she couldn't be. No one gets a full body skin transplant... #2 Even with Nika's selective memory, I'm sure the Petrova name would trigger him. #3 is currently the best bet.
Elsa is high society and has a fancy french surname, Elsa's mom called Nika trash and is Summer's aunt, Summer's parents also called Nika shit to his face... So the implication was that Summer's family is part of high society. They've probably left Wollust, because otherwise Nika could trace them down publicly, looking up their surname. Bella tells Nika Elsa is out of his league, so I can imagine all of Sasha's friends could easily be aware of who Summer is. And Sasha's friends seem to be mainly the redhead, the other brunette and Robin (of course Ayua who probably knows everything) The redhead shops in the same clothing store that Bella takes Nika, Robin's mom holds the bookclub in a mansion, so elite status is confirmed. All of Sasha's close friends seem to keep tabs on Nika, the redhead doesn't introduce herself, the other brunette we've not interacted with, Sasha does seem to know him, Robin starts introducing herself in a fake way to get info about Bella... so we don't know if they're pretending ignorance.
BUt even still, it's a bunch of loose connections. We've basically just got a mystery and we're trying to solve it with too little evidence of what happened.
I like that thought about the therapy - Noji gives two reasons for the therapy, both Bella, the initial one was because you triggered her (and even then it appears that Noji knows who Bella is, before they've met), then the last straw was disappearing on the night of the burglary. Amber seems pretty uninterested in dealing with Nika's more violent/criminal tendencies. It suggests she already knows more than she's letting on. The fact that Noji has waited so long to get Nika therapy also suggests she's more worried about how he'll deal with all the discoveries about what's going on behind his back ...pre-emptive therapy?
I also like the idea that each of the LI's has a shared trauma with Nika. Nia has the connection via Summer, Nami is obvious with her dark secret, Bella's sister might ne connected, and what happened to Sasha, Bella's sister and Summer is connected. Marla has a pre-existing history that goes back earlier than the car accident (she wants shared therapy with Nika, but not with Vic?) The Frohn's were known by Noji, but they're not high society, so she had to have known them to make comments about knowing a couple with two girls called Vic and Maja. Elsa has an obvious connection via Summer. SO about half of the supposed LI's might have some shared trauma. Sonya is unlikely to have any connection, Mila, well I think her mom probably worked for Leia in the nightclub at one point, but I've got no reason to think that... Nadia we know nothing about her secret yet, and the Benz's seem to have their own independent secrets.
When this was first posted (around the time WiaB was deleted from patreon) we were all still arguing over the Cyrus name and why it's such a downer. So at least this has stayed consistent, we're still arguing over roomies and landladies. We're going in circles and the circles are the hoops we have to jump through