after being turned into a Troll by Trylla with a changeling spell with her second daughter taking your place, after a week or so inside the mountain in the stone forest you run into a Troll that looks like a human girl

Hilda: "o- oh sorry I wasn't watching where I was going... I've just trying to adapt to being a troll... Hey you look like a human like me! Well used to be like me... Hey aren't you apparently my new little sibling that Trylla- I mean mom used a Changeling Spell on?"