I feel confident that if it's not what she wants when the situation becomes apparent to her, she'll simply bend reality to suit her as she always has. She now holds tremendous power if she chooses to wield it, and in particular is probably the only person now with power over Ferdinand. Lots of ways to solve it when you're an Aub.
Thank goodness it seems the Sigiswald path is off the table, that would have been deeply isolating and unfair.
I was totally nooooooo! keep going, I wanted to see what happened when Mestionora took her body!
Maybe we're going to get that from Ferdinand's POV.
And yes, I love the way they are actually two complementary gremlins to outsiders.