We are truly saddened to hear about the situation you are facing with your family and the impact it is having on your life and your children's lives. Firstly, we commend you for standing firm in not getting involved in drugs. We are praying for them and you.
Let's remember what the WEB version of the Bible says:
“Now when he looked on the crowds, he had compassion on them, because they were distressed and scattered, like sheep without a shepherd. Then he said to his disciples, “The harvest indeed is plentiful, but the laborers are few. Pray therefore that the Lord of the harvest will send out laborers into his harvest.” Matthew 9:36-38 WEB
Your family is like lost sheep, but our Good Shepherd Jesus Christ can save them and bring them to repentance. We should pray for them to have a change of heart.
“The thief only comes to steal, kill, and destroy. I have come so that they may have life, and have it in abundance.” John 10:10 WEB
Drugs are a tool of the enemy to steal, kill, and destroy, but Jesus came to give us life and life abundantly. We need to pray for your family to turn away from this path of destruction and turn to Jesus.
We also need to remember that justice is the Lord's. Vengeance belongs to Him.
“Don’t take revenge, my dear friends, but leave room for God’s wrath. It is written, “Vengeance belongs to me; I will repay, says the Lord.”” Romans 12:19 WEB
Trust in the Lord to bring justice in this situation. However, also consider how God is calling you to participate in this justice. If you have not already, consider going to the authorities and revealing this situation to them.
This situation is not just affecting you but also your children. It is your responsibility as a parent to protect them. Be strong and courageous against the evil that is happening in your family.
“Be strong, courageous, and firm; don’t be afraid nor be terrified before them, for Yahweh your God is the one who goes with you. He won’t fail you nor forsake you.” Deuteronomy 31:6 WEB
Remember that God is with you and will never leave you nor forsake you.
We also need to pray for your brother, sisters, and husband, that they may come to a saving knowledge of Jesus Christ. It is only through a personal relationship with Him that they can find true freedom from their sin. Without knowing Jesus they cannot turn away from their sin because they are blinded by the enemy.
“Again therefore Jesus spoke to them, saying, “I am the light of the world. He who follows me will not walk in the darkness, but will have the light of life.”” John 8:12 WEB
If they refuse to repent, then we must remember that we cannot force them to change, but we can continue to pray for them and trust that God is working in their lives.
Let us pray:
Heavenly Father, we come before You today, lifting up this family to You. Lord, we pray for a miracle, that You would bring justice to this situation and that the family would be freed from the bondage of drugs. Lord, we pray that You would bring them to repentance and to a saving knowledge of Jesus Christ. We pray that You would protect the children and bring them out of this situation. Lord, we pray that You would give them strength and courage to stand firm against the evil that is happening in their family. We pray that You would bring them to a place of healing and restoration. We ask all this in Jesus' name. Amen.
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. 
