Mr/Ms opinion, I agree with your idea except one. As long as she was willing to share his bed and concieve his baby, she might not have a problem to share a house with him. The problem is, she doesn't love him. She can stay with the guy to give a perfect life for her baby. But what about her? What kind of marriage is that going to be? We all know a marriage of convenience doesn't work these days. So she has to find a way to raise the baby alone. A child who grows without love will face many challenges in the future. I think she shouldn't get married only for the sake of the baby.