Yes, your parents died, and she is taking steps at living, but you want to hold her there to wallow in your misery. She also lives at the house technically. Are you planning on staying in every night to have bonding time with her or just take perverse pleasure in making her stay home when you do whatever the fuck you want? Or maybe you would like to move in with us? I tell great stories, and we could have weekend fishing trips - just the two of us.
I'm not discussing Katherine. What she wanted when I was drunk at a party isn't relevant. If you think you are going to use that to split us up, she will leave you without anyone at all. Let her be happy.