distraughtmom,
First, let me say that I think it's excellent that you acted on this as soon as you found out. I don't have time to address everything in your post right now, but I did want to mention a couple of things.
It is very common for abusers and those who enable them to belittle the victims and try to make them believe that "it's no big deal" or nothing really happened. In fact, it's classic. It makes you feel like you're talking to a brick wall or going crazy. It's simply a matter of trying to control you and the situation. It's a way to wear you down.
I'm glad you support your daughter. I can understand your doubts somewhat especially with the way your family is acting, but you were abused by the same man and treated the same way by the family as they are treating you an your daughter now. This seems to be a pretty obvious pattern repeating itself.
I'm sorry that your sister is acting like this, but your therapist is right. It's classic behavior. Please try not to blame yourself. It's got to be exhausting, especially living so near them. Just try to keep you and your family's safety utmost in your mind.
Is there someone that helped during the court process that you can contact to find out what happened at your father's hearing? This would make it much easier for you rather than having to contact your parents.
Please feel free to come to the forum and vent when you need to. No need to apologize.