Sometimes our needs grow and change. Just because she doesn't want another relationship right now, doesn't mean she won't want one in the future.
You said that she has difficulty forming close bonds with people. This is something that I can relate to, and perhaps you two are just what she needs right now. Maybe watching the love between you and your husband grow and remain will help her with her trouble attaching. Maybe an example of a loving relationship will be more benfical to her than a monogamous relationship of her own.
My advice would be to just love her. And let her see the love between you and your husband. Sometimes just witnessing love is enough to push past the negative feelings that one can have about it. Be patient with her. You get to watch her grow and overcome, and that could be an amazing adventure.
Take your time, talk about everything, and be supportive of her emotional needs and wants. Show her that she can trust love, and you may just find that all those bad experiences she has had start to seem less and less a part of her.
Perhaps setting some time aside just for her that you all have agreed on will help your husband with his jealousy. I'm not a big fan of rigidly dividing time, but maybe it will be best for you three. Perhaps if your husband has some time with just her as well, it will be easier for him to let you and her become closer. If they have a solid friendship, it might be easier for him to let you two spend time together.
A group conversation would probably benefit you all greatly. Talk about what he needs, what she needs, and what you need. Write it down if it's easier, and then find a way to make sure that everyone is getting what they need. There will probably have to be some compromise, but a compromise made out of love isn't really a sacrifice.
Best of luck, hun!
Last edited by MoonFairy; 10-28-2009 at 05:41 AM.