and aurora's personal visit resulted in karina's complete humiliation in chapter 5.
aurora throwing leftovers to her without ever properly explaining her intentions, while wielding all the authority karina once had was the final blow to her guts.
a realistic option to reconcile the sisters would be if aurora renounces her title and her marriage or publicly rehabilitates her sister and lifts the exile, but i doubt that the author will go with that.
Yes, from Karina's perspective; not from Aurora's, because up until the wedding ceremony that took place years after the "castle incident", Aurora had no idea as to how Karina felt. I'd argue she still doesn't, but that's because Karina has never been one to talk about her problems and struggles with others, and Aurora had very little chance of significant contact with Karina from the time she was taken away to be Queen Consort, up to Orlando annulling their engagement and exiling her.
Aurora's actions have
all been in the context of what she thought would help Karina and/or make her happy. Karina spent their childhood doing just that for Aurora, and she sought to reciprocate in the manner she assumed would be equivalent. She just didn't know that Karina's perception of
all of it, and a whole bunch more, over the span of their adolescence.
The way you're choosing to phrase everything is entirely taking Karina's side and how she perceives things. She's the protagonist, so that's understandable,
but we do have a lot more context for the other characters now than we did at the point of chapters 3-5, and continuing to only parse Aurora's actions through the lens of another character--particularly one we
know has a warped view of things--starts to seem unfairly judgmental.
Aurora's made a right mess of things, but not with the aim or intent that Karina believes she had. That's a key point, and is what I'd argue one of the central themes of the series: that perspectives and prejudices are clouding the truth of what's actually transpired, and that the truth needs to be sought out and uncovered, or else tragedy will befall them all.
And I'm not even sure if that's a "realistic" option, though I'm not going to guess at where the author's headed from here. But as of now, there's no reason for Aurora to renounce being Queen Consort, especially if the Crown really is corrupt or otherwise doing something nefarious; her removing herself from Orlando's side means she'd lose her existing leverage with him, and we've seen her stave off his desire to send an actual army after Karina twice now (chapter 3, and again in chapter 12)--
and the second time, Aurora actively stood up to him in front of assembled nobility, in a much more aggressive manner than she did in chapter 3. Aurora's own temperament and demeanor has changed over the course of the series, and so giving up the power she's gained would arguably make her aim of protecting Karina all the harder.
As for making a public declaration of absolving Karina--that also wouldn't fly at present, given she
still has to contend with Orlando, and with the King himself. Until the Crown's power can be somehow diminished--in whatever way that plays out, which I assume is also part of Eve's own arc within the story, being a scribe/sleuth/etc--Aurora still has her hands tied, and she would have to figure out how to rehabilitate Karina's image among the nobility and reverse the years-long rumor mill against her sister.
But before that, she needs to find Karina, and start the process of addressing the tensions and problems between them. Nothing can happen before that, as Aurora could move heaven and earth to change Karina's fate in the eyes of their kingdom, and it wouldn't matter while this severe "misunderstanding" between them persists.