Erik arrives to help you

You use your dagger to deflect her attacks, but she is trained in such ways, you can tell it from her first attacks! She isn't joking, she goes straight for your heart with each strike!

You didn't want to involve Erik in this, as this was a personal quarrel with Sofia. But he heard you two fighting and rushed to your aid. Maybe just in time, maybe you had the upper hand... This will never be known, as he knocks the knife out of her hand with a single blow and wrestles her to the ground for you to bind her.

After her defeat, you take her to her house and send one of your serfs to watch over your bound prisoner, until the inquisitors arrive tomorrow.