We are truly saddened to hear about your dad's critical condition and the complex family dynamics at play. Let's bring this situation before the Lord in prayer and seek His will according to His word.
Firstly, we acknowledge that it is only by the name of Jesus that we have access to the Father (John 14:6 If you had known me, you would have known my Father also. From now on, you know him, and have seen him.) and that there is no other name by which we can be saved. (Acts 4:12 There is salvation in none other, for neither is there any other name under heaven, given among men, by which we must be saved.) So we pray this all in Jesus name.
Let's pray for your dad's physical healing and recovery. The Bible tells us that Jesus went about healing all manner of sickness and disease (Matthew 4:23 Jesus went about in all Galilee, teaching in their synagogues, preaching the Good News of the Kingdom, and healing every disease and every sickness among the people.), and that He is the same yesterday, today, and forever (Hebrews 13:8 Jesus Christ is the same yesterday, today, and forever.). Therefore, we can still expect Him to heal your dad today. We pray for the doctors to have wisdom and understanding to be able to manage the situation properly.
However, we also recognize that your dad has hardened his heart towards Christ. Let's pray for his spiritual healing as well. God does not want anyone to perish but for all to come to repentance (2 Peter 3:9 The Lord is not slow to fulfill his promise, as some count slowness, but is patient toward you, not wishing for any to perish but for all to come to repentance.). We pray that this situation will be a wake-up call for your dad and that he will turn to God in repentance and faith.
Regarding the family drama, we pray for peace and unity. The Bible tells us to live in peace with everyone (Romans 12:18 If it is possible, as much as it is up to you, be at peace with all men.) and to forgive as we have been forgiven (Ephesians 4:32 Be kind to one another, tenderhearted, forgiving each other, just as God also in Christ forgave you.). We pray that this situation will bring your family together and that any bitterness or unforgiveness will be released.
We also want to address the situation with your dad's girlfriend. While we understand that she played a crucial role in saving his life, we must remember that God's design for intimacy is within the bounds of marriage between a man and a woman (Hebrews 13:4 Let marriage be held in honor among all, and let the bed be undefiled: but God will judge the sexually immoral and adulterers.). We pray that this situation will bring conviction to both your dad and his girlfriend and that they will repent and turn to God's design for relationships.
Lastly, we pray for you, your mom, and your sisters as you travel to see your dad. We pray for safety and for the Holy Spirit to comfort and guide you during this time (John 14:26 But the Counselor, the Holy Spirit, whom the Father will send in my name, he will teach you all things, and will remind you of all things that I said to you.).
Father, we lift up Zairtuinhold's dad to You, asking for Your healing touch on his body and soul. We pray for the family, that You would bring peace and unity, and we ask for travel mercies for Zairtuinhold, their mom, and sisters. We also pray for conviction and repentance for Zairtuinhold's dad and his girlfriend. We ask all of this in Jesus' name.
**Prayer Group Update!** 
Let's continue lifting up our brothers and sisters in Christ. Remember, God is faithful and He hears our prayers. "Cast your cares on the Lord and he will sustain you; he will never let the righteous be shaken." (Ps 55:22)
For any requests to be removed or updated, please feel free to let us know. We're here to support and pray together.
Let's lift up 
for healing. "Lord, touch & restore her health. 'I am the Lord, who heals you.' (Ex 15:26) Grant her strength & comfort. 'Cast your cares on the Lord.' (1 Pet 5:7) Trusting Jesus for her recovery!" 
