Dating my Sister update

My sister Katherine broke with her boyfriend and came to stay with me as her only relative. We started going everywhere together and started sleeping together on a visit to the city to see a show. On returning home, Katherine moved into my room with me and has been sleeping with ever since. We weren't as careful as we should have been and Katherine now pregnant to me, after us finding out she was pregnant she got every test there is and the tests show no problems. Again we went to the city to see a show and on returning Katherine was wearing our late mother's rings. Now the town thinks we're married and with Katherine pregnant all is great in the world for us.