We understand that you are dealing with spiritual warfare from someone practicing voodoo. First, we commend you for your faith in Jesus Christ and your fellowship with God. It is only through the name of Jesus that we have authority over any spiritual darkness, as it is written:
And these signs will accompany those who believe: in my name they will cast out demons; they will speak with new languages; they will take up serpents, and if they drink any deadly thing, it will in no way hurt them; they will lay hands on the sick, and they will recover." WEB Mark 16:17-18
And whatever you shall ask in my name, that will I do, that the Father may be glorified in the Son. If you shall ask anything in my name, I will do it. WEB John 14:13-14
We must remember that our battle is not against flesh and blood, but against the spiritual forces of darkness. Therefore, let us pray together for your situation:
Father God, we come before You in the mighty name of Jesus Christ, seeking Your divine intervention and protection for our fellow believer. We stand against the forces of darkness that are being used by this practitioner of voodoo, and we declare that her evil antics have no power over our sibling in Christ. Lord, we ask that You hasten Your hand to smote and admonish this reprobate voodoo practitioner, abating her evil antics and removing her from our fellow believer's life, as she is a hindrance to their Christian walk with You and Your precious Son, Jesus Christ. We pray for her soul as she is lost and deceived by Satan. As believers in Christ, we also pray that you would expose and help her be delivered from the demonic power controlling her.
Please pray for her salvation and to be delivered from her sins. Our battle is not against flesh and blood, but against the rulers, against the authorities, against the world rulers of this darkness. WEB Ephesians 6:12
We ask this in the mighty name of Jesus Christ, who has all authority in heaven and on earth. Amen.
Continue to stand firm in your faith, and resist the devil, and he will flee from you. (WEB James 4:7) Put on the whole armor of God, that you may be able to stand against the wiles of the devil. (WEB Ephesians 6:11) Trusting in God, we need not fear the spells, curses, and witchcraft that you are facing. Greater is He that is in you than he that is in the world. (WEB John 4:4). The same power than raised Jesus from the dead lives in you.
Let us encourage you to continue to pray, speak out loud, and praise God's word in the Bible as our sword and shield. As believers as Christians in Jesus Christ, we have the victory through Jesus Christ who overcame the world.