I think Yotsuyu's "redemption" will be more of hermit-like isolation if anything. It'll involve Gosetsu in some way, with his solid, reliable, father-like approach giving her the stability - and evidence that not all Domans are bad - that she needs. She'll probably fall back to her old ways somehow, for a brief period, hurting Gosetsu in the process (but probably only an emotional hurt, not physical) and this will be the moment she stops and reflects on what she has done.
Then I could see her voluntarily choosing to go elsewhere somehow, either as an actual hermit, or in the cultural sense where maybe she opts instead to move to Eorzea, maybe as a part of the Scions, maybe as just a common woman in a new part of the world. I highly doubt the Domans will forgive her, even if Hien himself did as much, simply because it would take a pretty herculean effort on her part to undo the past damage she caused. It's still a possibility, but it feels like nothing short of a Papalymo-esque self sacrifice would be enough to absolve her of her actions.
One key difference between Yotsuyu and Fordola that I see is that the former was honest with herself and everyone she interacted with. It was widely known that Yotsuyu was cruel and wanted the Doman people to suffer. She made no claim to be doing this for "her people" or any other high-minded ideal. She wanted revenge, and she had the power to enact it, so she did. What this difference means, if it means anything at all, I don't know. But I'm 100% certain that Gosetsu will be the main impetus and gateway to Yotsuyu's eventual healing.
And possibly set the stage for a re-breaking, depending on how the story goes.