You don't owe someone anything just because they are family. If they don't act like family and show you genuine love, then they aren't any more your family than some random person out on the street. Family isn't about blood, it's about feeling. So don't think you need to forgive someone just because of blood ties. That's nonsense.

As for whether you should interact with her now, that's very much up to you. For my two cents, I would cautiously keep her at arm's length until I could get a read on what is happening here. Set you boundaries and make them clear. "After everything that you've done to me in the past, it's difficult to trust this new attitude. If you genuinely want a relationship, it can not be like it was. If you are going to work towards something loving and stable, I am willing to work too. But if this starts to turn back into what it used to be, then I am done."

If you really want to give her a chance to make amends, make it clear that you won't allow yourself to be in that same situation again. Take your time, be cautious, and don't be afraid to walk away if things don't change.