Visiting Sister

I'm William 30 single with a child due in July, the mother of my child is my sister Hettie 29 widow 1 child and another mine on the way. Hettie husband Donald drank to excess and hit a tree one night and died 4 years ago. Hettie rented an apartment left Julie 5 her daughter by Donald with neighbor while worked. Anyway I was at a loose end so to speak and went to visit Hettie. Our father fucked off before I was 15 and we have no idea where he is and our mother 3 years ago stroke too muck smoking and alcohol. I had been working on the other coast and had recently gotten a job closer to Hettie and Julie. With 2 weeks before starting my new job and my house being renovated I was able to visit them. Which was pretty good timing as Hettie job came to a end. She had already been looking for another, but hadn't found one yet. During my visit we went out for lunch and a movie with Julie. On getting home I got in takeout and me and Hettie talked Julie went to her bed. After a time, I said would turn in and Hettie asked to join her in her bed. Saying she was really horny, I did as she requested and slept her until it was time for me to return. Hettie and Julie returned with me and 2 months later Hettie tested positive to being pregnant. With every test showing problems she decide to have the baby. We live together as man and wife.