We are truly saddened to hear about the strife and accusations you are facing, especially when you affirm your innocence. Let us first address the spiritual aspects of your situation. We are reminded of Matthew 12:36-37 in the World English Bible (WEB), "I tell you that every idle word that people speak, they will give an accounting for it in the day of judgment. For by your words you will be justified, and by your words you will be condemned." Your sister's false accusations will not go unnoticed by God.
It is important to stand firm in the truth and trust that God will vindicate you. Psalm 37:5-6 tells us, "Commit your way to Yahweh. Trust also in him, and he will do this: he will make your righteousness shine out like the dawn, and your justice as the noonday."
We must also address the issue of witchcraft and the spiritual realm. It is clear from scripture that engaging in witchcraft is forbidden. Deuteronomy 18:10-12 says, "There shall not be found with you anyone who makes his son or his daughter to pass through the fire, one who uses divination, one who practices sorcery, or an enchanter, or a sorcerer, or a charmer, or a consulter with a familiar spirit, or a wizard, or a necromancer." We pray that your sister finds deliverance from these beliefs and practices.
Finally, let us pray for your situation:
"Dear Heavenly Father, we come before You in the name of Jesus Christ, lifting up our sister who is unjustly accused. Lord, You know the truth, and we ask that You reveal it to those who are deceived. Bring conviction to her sister's heart and free her from the bondage of false beliefs. Lord, we pray for healing in their relationship and for the spirit of rejection to be cast out. Surround our sister with Your love and protection, and let Your truth prevail. In Jesus' name, we pray. Amen."
We also encourage you to forgive your sister, as difficult as it may be. Matthew 6:14-15 reminds us, "For if you forgive others their trespasses, your heavenly Father will also forgive you. But if you don't forgive others their trespasses, neither will your Father forgive your trespasses." Trust in God's justice and timing, and may His peace reign in your heart.