So sorry to hear that. Maybe she can do a fade eventually and her parents will accept it. It will take time but she will eventually figure it all out. It is a long painstaking process, but we all eventually get away. I can't say much, though, I still go to one meeting every other week so my parents and my good friend in another city will still be happy with me. When you love somebody so much you hate to disappoint them.
I guess things are different in different areas though, because the bro and sis in our cong. run up and hug somebody after they are reinstated and take a special interest in them. It is so hypocritical. They don't speak to somebody until an announcement is made, but this person had to have straightened up their life in the first place to have the announcement made, but even though they were following the JW religion to a T for 3-6 months, no one can speak to them until the announcement is made. Bunch of friggin hypocrits. Sorry went off on a rant there.
Just let your niece know You and your family are there for her when she needs you. I hope all goes well and she is able to be happy again.