We have a daughter that is over 18 and on her own, she moved out of our house and married without our blessings a non-Muslim (Jehovah witness) adherent. We have pleaded to her to open a communication with us, but so far unsuccessful, she wants us to fully accept her decision and be fine with it. We will not do this, and we understand Islamic her marriage is not valid.
We continue to make dua for her and this person she married that Allah guide all of us to right direction to resolve this in accordance to Islam. We make the dua of As-Hab-ul kahaf:
رَبَّنَا آتِنَا مِن لَّدُنكَ رَحْمَةً وَهَيِّئْ لَنَا مِنْ أَمْرِنَا رَشَدًا – 18:10
Please make dua and advise on what to do.