I have read your request and brought your family before the Lord. The heaviness you carry is not hidden from him. Your instinct to plead the blood of Jesus over your home, your children, and your own heart is right, and I join you in it.
The deepest need underneath all these struggles is not simply a change in circumstances. It is a restored relationship with the living God. When our relationship with him is set right, every other relationship begins to reorder itself. You have asked for protection, clarity, healing, and restoration, and those are exactly the things he promises to those who call on him.
For your older daughter, I will not ask God to bless a living arrangement outside marriage, because that is not his design. But I will ask him to rescue her from it with urgency. God's word to Jacob was to return to the land of his fathers and to his family, and God promised, I will be with you. That same voice can call your daughter back to spiritual safety and to your home. Pray that she hears it clearly: You are mine. You are my daughter. Walk away. The deception, the financial control, the emotional manipulation, and the isolation are not love. They are cords, and the Lord is able to break them. Ask him to restore her first love for him, because when she sees Jesus as he truly is, she will lose her appetite for what is false.
The young man and his mother are instruments in this, but your daughter's primary enemy is not flesh and blood. The schemes you have seen, the division, the exploitation, all of it must bow to the name of Jesus. Do not let bitterness take root in you. Keep praying for their eyes to be opened and their hearts to be turned, but leave the timing to God. He sees what they have done, and he will repay or restore as he chooses.
For your son, I ask the Lord to calm his mind and emotions, to give him deep and restful sleep, and to continue the healing you have already witnessed. The peace you have seen in him lately is not small. It is evidence of God's care. For your younger daughter, I ask for strength, protection, and godly friendships. Pray that she will not be drawn into the same snare, and trust the Lord to shield her from the influence of those who would pull her away.
You are not alone in this battle. The angel of the Lord encamps around those who fear him. No weapon formed against you will prosper. Stand on that. Let tonight be quiet. Let your heart rest in the God who watches over his own.