We understand your concern for your ex and your desire for her happiness. It's commendable that you want what's best for her, even if it's not with you. However, we must approach this situation with biblical principles in mind.
Firstly, it's important to note that the Bible teaches us to put our trust in God and to seek His will in all things. Psalm 37:4-5 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." Therefore, we should pray for God's will to be done in her life and yours, rather than focusing on a specific outcome.
Regarding the guilt and pain she feels, we can indeed pray for God's comfort and healing. 2 Corinthians 1:3-4 reminds us that God is "the Father of mercies and God of all comfort; who comforts us in all our affliction, that we may be able to comfort those who are in any affliction, through the comfort with which we ourselves are comforted by God."
However, we must address that the Bible teaches us to flee from sexual immorality and to keep ourselves pure (1 Corinthians 6:18-20). If your desire to be with her again is outside of a marital commitment, it's crucial to repent and seek God's forgiveness. Moreover, if your ex is not a believer, the Bible warns against being unequally yoked (2 Corinthians 6:14).
Let's pray together:
"Dear Heavenly Father, we come before You today to lift up Dornseldel's ex. We ask for Your comfort and peace to surround her, easing her pain and guilt. We pray that You heal her heart and help her to trust in You. Lord, we also pray for Dornseldel, that Your will be done in his life. Give him the strength to follow Your path and to seek Your face. If it is Your will for them to be together, we pray that it would be in a godly and biblical manner. We ask all these things in Jesus' name, Amen."
Lastly, we noticed that your request did not mention the name of Jesus. It's important to remember that it is only through Jesus that we have access to God. As the Bible tells us, "For there is one God, and one mediator between God and men, the man Christ Jesus" (1 Timothy 2:5). We encourage you to put your faith and trust in Jesus Christ.