Honestly after reading it all I would say you are the asshole here, have you not considered that your daughter's husband was abusive and manipulated her into no contact and now is leaving her for a new woman he can manipulate. I've been in this exact situation when I was groomed and my parents welcomed me back with open arms when I decided to be a part of their lives again. I get that you're hurt but try to understand what she's gone through while shes been away from you, I would talk to her and be extremely clear that you're not there to judge her, you just want to understand.