We have heard your heart and we carry your burden with you before the Lord in Jesus' name, especially as you are walking through a difficult season and feeling wounded by your sister.
We understand how exhausting it is to be treated unkindly and differently by someone in your own family, and to feel that her kindness only appears when she wants something from you such as childcare. That kind of conditional treatment is painful and confusing, and we do not take lightly how tired you feel. At the same time we want to gently speak truth over this situation as Scripture calls us to.
The behavior you describe in your sister, being unsupportive, unkind, mean and selfish toward you, your mother, your father and your other sister, and then switching to niceness when she needs help, is not reflecting the love of Christ. We must rebuke that pattern because it does not align with God's Word. Ephesians 4:31-32 says Let all bitterness, wrath, anger, outcry, and slander, be put away from you, with all malice. And be kind to one another, tenderhearted, forgiving each other, just as God also in Christ forgave you. And 1 John 4:20 says If a man says, I love God, and hates his brother, he is a liar; for he who does not love his brother whom he has seen, how can he love God whom he has not seen. A professing Christian is called to bear fruit in keeping with repentance and to love family sacrificially, not to use them. Her actions need to be brought into the light in love, and if possible through a loving, honest conversation as Matthew 18:15 teaches, If your brother sins against you, go, show him his fault between you and him alone. We encourage you to seek wise and godly counsel, perhaps a pastor or mature believer, to help you address this pattern with her in a biblical way rather than carrying it alone.
We also hear you saying you no longer want a relationship with her at all. We understand that desire to pull away to protect your heart, and Scripture does call us to guard our hearts and to not be unequally yoked with those who persist in harmful behavior, and to set healthy boundaries. Yet we also want to encourage you not to let hurt harden into bitterness or a permanent closing of the door to reconciliation. Hebrews 12:15 warns us to look carefully lest there be any man who falls short of the grace of God, lest any root of bitterness springing up trouble you, and many be defiled by it. And Romans 12:18 says If it is possible, as much as it is up to you, be at peace with all men. This does not mean you must subject yourself to ongoing mistreatment or be available to be used, but it does mean we are called to forgive from the heart as Christ forgave us, Colossians 3:13, to not repay evil for evil, Romans 12:17, and to love and pray for those who mistreat us, Matthew 5:44. Forgiveness releases you before the Lord even when trust must be rebuilt slowly and with clear boundaries. It is right to say no to being manipulated, to limit what you do for her when it enables her unkindness, and to speak the truth in love with gentleness, Proverbs 15:1, Ephesians 4:15, while still keeping your heart open to what God might do to convict and restore her.
In this difficult time you are going through, we want you to know God sees you and is near to you. Psalm 34:18 says Yahweh is near to those who have a broken heart, and saves those who have a crushed spirit. And Isaiah 41:10 says Do not be afraid, for I am with you. Do not be dismayed, for I am your God. I will strengthen you. Yes, I will help you. Yes, I will uphold you with the right hand of my righteousness. He is your refuge when family support fails.
We noticed your request did not mention the name of Jesus Christ. We want to gently remind you that it is only through Jesus that we have access to God and that our prayers are heard. John 14:6 says Jesus said to him, I am the way, the truth, and the life. No one comes to the Father, except through me. And Acts 4:12 says There is salvation in none other, for neither is there any other name under heaven, that is given among men, by which we must be saved. We encourage you to place your trust fully in Jesus Christ for salvation and for daily help, believing that He died for your sins and rose again, and confessing Him as Lord, Romans 10:9, so that you may walk in His grace and power to love and forgive even when it is hard.
We pray together with you now.
Father in heaven, we come before You in the precious name of Jesus Christ and lift up our dear sister to You. You know the weariness in her heart, the pain of being mistreated by her own sister during a difficult time, and the history of unkindness toward her parents and family. Lord, we ask You to comfort her, to strengthen her, and to uphold her with Your right hand. Heal her broken heart and guard her from bitterness. Help her to forgive as You have forgiven her, and give her wisdom to set healthy, loving boundaries that honor You. We ask You to convict her sister where she is acting selfishly and unkindly, to open her eyes to how she is treating her family, and to bring her to genuine repentance and to walk in kindness and tenderheartedness. Bring truth into the light and if it is Your will, bring reconciliation and peace to this family. Lead them both to seek You first and to love one another as Christ loves us. Give our sister discernment, courage to speak the truth in love, and surrounding support from mature believers. We ask all of this in Jesus' name, trusting in Your mercy and Your power to restore. Amen.
We encourage you to continue to bring this to the Lord daily, to stay rooted in His Word, to not isolate yourself but lean on godly community, and to keep doing good without growing weary, Romans 12:21 says Do not be overcome by evil, but overcome evil with good. We are standing with you in prayer that God will bring healing to your heart, wisdom for your next steps, and His peace that passes understanding to guard you.