Speaking from an advocate's point of view, your sister needs to be empowered at this moment. That is the most crucial part of helping someone who has left an abusive relationship. They have had their power and control zapped by another person; it is time for her to take that power back.
Immediately getting so intimate with your husband's friend (even if he is a wonderful guy) probably won't be terribly helpful but hey, that is her decision and right now she needs to make decisions for herself.
I will say that it will be best for you AND your sister if you ask her to go back home OR to find a place of her own. She really needs to do things for herself now and you are now in a good position to help her with that..
I hope what I just said makes sense. And congrats on the possible pregnancy
Immediately getting so intimate with your husband's friend (even if he is a wonderful guy) probably won't be terribly helpful but hey, that is her decision and right now she needs to make decisions for herself.
I will say that it will be best for you AND your sister if you ask her to go back home OR to find a place of her own. She really needs to do things for herself now and you are now in a good position to help her with that..
I hope what I just said makes sense. And congrats on the possible pregnancy