Lesbian Sister

My sister Marie came out as a lesbian at 18, she is now 24 and has moved in with me after her breakup with her partner Carol 31. She was in the relationship for 4 years and she took the breakup very hard. I'm Alex 27 her only sibling and only one who would take her in. As our parents are born again Christians and won't have anything to do with Marie as long as she wants to be a lesbian and they have told her to repent her evil ways. I, on the other hand, don't believe their crap and have said so and I have been excommunicated from the family. Which I have taken to be a good thing and never expect to be invited back into the family. I make a good living selling things on the internet and working in computer repairs mainly. Long story short Marie is quite good looking when she dressed up and shortly after her moving with me. She got very drunk and I took advantage of her, I was horny and she looked so sexy and I started to feel her up and ended up fucking her and again in the morning. She I should have realized as a lesbian didn't take the pill or any other type of contraceptives precautions. So now she is 5 months pregnant to me, she sleeps with me every night and we act like we're married. Last week Carol came around to see Marie and wanted to try again and even marry Marie saying her life (Carol's) is nothing without her(Marie). But the thing that shocked me seeing Marie pregnant only made Carol want her more and also to have a baby by me. Marie is thinking about it and Carol has also just moved with us and sleeping alone, till Marie decides what she wants. I'm letting Marie make up her mind and haven't said anything about her and Carol. Carol isn't bad looking, but is stockier build than Marie. But I would fuck her if given the chance anytime she wanted. Marie is very excited about renewing her relationship with Carol I think, but isn't rushing to a decision.