We understand your concern and will join you in prayer for your daughter and her situation. Let's first align our hearts with God's will and trust that He cares for your daughter even more than you do. It's important to remember that God desires that we are not unequally yoked with unbelievers, for what fellowship has righteousness with unrighteousness? And what communion has light with darkness 2 Corinthians 6:14 WEB?
Your daughter's increased drinking habit is also a concern. The Bible warns us not to be drunk with wine, wherein is excess, but be filled with the Spirit Ephesians 5:18 WEB. We will pray that God will deliver her from this habit and fill her with His Holy Spirit.
Let's pray together:
Dear Heavenly Father,
We come before You in the name of Jesus Christ, lifting up our sister and her daughter. Lord, we ask that You will come into her daughter's life and deal with whatever is not in alignment with Your will. We pray that You will touch her heart and reveal to her Your perfect will for her life.
Lord, we ask in Jesus Christ name that You will move this boyfriend out of her life if he is not Your will for her. We pray that You will cut the cords of this relationship if it is not pleasing to You and keep her abstinent from sex as all sexual activity outside marriage is immoral. We ask that You will break and destroy any evil strongholds that may have been formed in their lives. We also pray in Jesus name that You will cause their hearts to change towards one another, that they may find they have no interest or anything in common with one another if this relationship is not from You.
Father, we also pray for her daughter's drinking habit. We ask that You will deliver her from this habit and fill her with Your Holy Spirit. May Your Spirit lead her and guide her in the paths of righteousness.
Lord, we ask that You will give our sister Your peace and comfort. Help her to trust in You and Your timing. Give her the wisdom and strength to support and guide her daughter in accordance with Your will.
We ask all these things in accordance with Your will and in the powerful name of Jesus Christ. Amen.
Remember, it is by the name of Jesus Christ that we have access to God. As it is written, For there is one God, and one mediator between God and men, the man Christ Jesus 1 Timothy 2:5 WEB. Continue to trust in God and His timing. Be patient and persistent in your prayers. May God's peace and comfort be with you and your daughter. Be encouraged you are not the only one praying for your daughter. The LORD is close to the brokenhearted, and saves those who are crushed in spirit Psalm 34:18 WEB.
Prayer Focus: God, Thank You. Thank You for loving me. God, I ask You in Jesus’ name bless me with everything that I stand in need of and everything You want me to have. Bless me to know You in truth, fall in love with You with all my heart, mind, soul, body, and strength and never fall out of love with You. Bless me to have an ever growing closer stronger, more intimate relationship with You. Bless me with the love, desire, strength, and the spirit of obedience to always delight myself in You, seek first Your kingdom, and Your righteousness. Help and strengthen me God to always respect and obey You. Bless me to trust You with all my heart, acknowledge You in all my ways, and lean not to my own understanding. 
