We understand your concern for your daughter Sierra, her husband, and their two daughters. Let's come together and intercede for them and their situation. We are grateful to read your request is in Jesus' name, for it is only by His name that we have access to God.
Firstly, let's remember there is power in prayer and in the name of Jesus. As it is said:
"Again, truly I tell you, that if two of you agree on earth concerning anything that they will ask, it will be done for them by my Father who is in heaven. For where two or three are gathered together in my name, there I am in the middle of them." Matthew 18:19-20 (WEB)
and,
"In that day you will ask me no more. Most certainly I tell you, whatever you will ask of the Father in my name, he will give it to you. Until now, you have asked nothing in my name. Ask, and you will receive, that your joy may be made full." John 16:23-24 (WEB)
Since you sense the darkness over their family, pray for freedom from bondage and for deliverance. Regarding the control and the OCD condition, we need to seek God's intervention and deliverance:
"If the Son therefore will make you free, you will be free indeed." John 8:36 WEB
God may use this experience for their good when they love Him. We should pray that they will indeed turn to Him and look unto Him in their despair:
"And we know that all things work together for good to those who love God, to those who are the called according to his purpose. For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren." Romans 8:28-29 WEB
and,
"Look to me, and be saved, all the ends of the earth; for I am God, and there is none else." Isaiah 45:22 WEB
We also need to pray and hope for your family to be reunited with Sierra and her family. Also, come before God begging that He will fill their lives with His peace, love, joy, and hopefully come to saving grace in the name of His Son.
Let's bow our heads:
Lord, our God in Jesus Name, hear our cry after your people for deliverance. You are the God of this earth and we ask that you heal this family, bring them into a safe and fruitful place with You. Free them from any darkness and let them have a relationship with You both now and into eternity. We pray that the power of The Gospel of Jesus Christ will be unleashed in their lives. As they seek You, reunite them with the family according to your will.
At the same time, God, whatever the husband may be doing or not doing, and whatever he is suffering, we ask You to lift from him or correct in him that which is hurting the family or Your anger. If this is mental illness or other medical issues we ask you for a healing. If it is spiritual issues we especially ask for your deliverance.
We ask this knowing,
"if my people, who are called by my name, shall humble themselves, and pray, and seek my face, and turn from their wicked ways; then will I hear from heaven, and will forgive their sin, and will heal their land." 2 Chronicles 7:14 WEB
If they are already saved Lord, use this trying time of theirs to bring them beyond what they were before. Help Lorard as they interceed for their daughter. Guide them to make the right decisions about dealing with the family issues.
In Jesus Name we ask. Amen
Thankfully, God knows every detail of the situation and He is working behind the scenes. Stand firm in faith, knowing that He is at work and He loves Sierra, her husband, and their daughters more than we ever could. Let's continue to pray together until we see God's breakthrough in their lives.
We are also praying for you, Lorard, and remember the same principles apply to you as well.