We understand the distressing situation you're facing, Helen, and we're here to stand with you in prayer and counsel. Firstly, let's address the heart of the matter: no weapon formed against you shall prosper (Isaiah 54:17, WEB). Curses and evil intentions do not have power over you when you belong to Jesus Christ.
However, we must ensure that our faith is firmly placed in Jesus Christ. It's important to note that it is only through His name that we have access to God, as it is written: "In no other is there salvation, for neither is there any other name under heaven, that is given among men, by which we must be saved!" (Acts 4:12, WEB). If you haven't already, make sure to put your trust in Jesus Christ for your salvation.
Now, let's pray together:
*Dear Heavenly Father, we come before you in the mighty name of Jesus Christ. We stand against any curses or evil plans directed towards Helen, her twin sister, and her cousin. We ask, Lord, that you would surround them with your favor as with a shield (Psalm 5:12, WEB). Vindicate them, O Lord, for they have not wronged this family member, but have shown respect and kindness. We pray that you would bless their mother for her wise discernment, and we ask that you would soften the heart of the family member who seeks their harm. Bring peace to their family, and let your will be done in their lives. Protect them from harm, and guide them in the paths of righteousness for your name's sake (Psalm 23:3, WEB). In Jesus' name, we pray. Amen.*
Lastly, we exhort you to love your enemies and pray for those who persecute you (Matthew 5:44, WEB). Continue to show respect and kindness, as you have been doing. Remember, Helen, that God works all things together for good for those who love him and are called according to his purpose (Romans 8:28, WEB). Trust in Him, and He will make your paths straight (Proverbs 3:5-6, WEB).