Honestly it's so unlikely but I'd much prefer if she just got with kiel, even if the prince wouldn't necessarily treat her badly he seems like such a bad fit.
Even if her royal family was shit he still killed them, and she's spent a lot of her life fearing him, you really gonna just get with that long term most likely? Plus she talks about freedom quite a bit, being royalty again would be so far from that. Kiel may have a high position too, but I doubt his responsibilities would be nearly the same level. She's never really had any bad experiences with him either, which is a big positive.
Plus he just seems like a nicer guy in general, even if they're both 'nice' to a degree that ML types are.