Father,
I pray that You will reveal "Your" love to this couple. Father, they are trying to do everything on their own. Father, as You have said in Your word, "Lean not unto thy own understanding, in all thy ways acknowledge Me and I will direct thy path."
Father, send Your Holy Spirit to intervene if thy will into this union. Allow them to see what they are doing to one another and to their families. Father, protect their child in the mist of this anger and confusion.
Father, I am praying for healing in marriages right now. Father, this sacred union is under attack from the enemy.
Father, bring Your love into this marriage. Bring Your forgiveness into this marriage. Father, allow them to stop and recognize that their marriage is under attack. Open their hearts with pure love. Father, reveal to them why they got married.
I ask this in Jesus Holy name. Amen!

My dear soul, this marriage must first be turned into the hands of our Father. These two must ask God to come into their hearts, minds and souls. God does not force Himself on anyone. This is something that they must want as well.
Once they open their hearts to allow God to work on this marriage, it will blossom with knowledge, wisdom, and understanding. Pray with your daughter. Allow God to use your vessel to help them understand His love.