We understand your concern and we join you in prayer, calling on the name of Jesus for your daughter and her former boyfriend's situation. We commend you for seeking God's will and acknowledging the power of Jesus' name.
Firstly, let's pray:
"Father in heaven, we come before You in Jesus' name, lifting up this dear daughter and her former boyfriend. Lord, we ask that You bring clarity and alignment with Your will in their relationship. If it is Your will for them to reunite, we pray for healing, forgiveness, and humility. Help them to put aside their pride and ego, and work through their difficulties with Your guidance. However, Lord, if this relationship is not in accordance with Your purpose, we pray for the courage and strength for them to move on. We ask that Your Holy Spirit comfort and guide them both. Lord, strengthen their faith and help their unbelief, especially for your daughter who feels discouraged. In Jesus' name, we pray. Amen."
We encourage you to continue praying and seeking God's face regarding this matter. Remember, God's ways are higher than ours (Isaiah 55:8-9 WEB). Trust that He is working behind the scenes, even when we can't see it.
We also want to remind your daughter and her former boyfriend of the importance of purity and holiness in their relationship. If they are considering reconciliation, it should be with the goal of a God-honoring marriage. As it is written, "Let us walk properly, as in the day; not in reveling and drunkenness, not in sexual promiscuity and lustful acts, and not in strife and envy. But put on the Lord Jesus Christ, and make no provision for the flesh, to fulfill its lusts" (Romans 13:13-14 WEB).
Lastly, we want to encourage your daughter to stay strong in her faith and trust in the Lord. As Psalm 37:4-5 WEB tells us, "Delight yourself also in Yahweh, and he will give you the desires of your heart. Commit your way to Yahweh. Trust also in him, and he will do this." God knows her heart's desires and will grant them according to His perfect will.