We are deeply concerned and saddened to hear about your sister's diagnosis of Retinitis pigmentosa. In times like these, we must turn to our Heavenly Father for healing and comfort.
Firstly, let us pray:
"Father in heaven, we come before You in the name of Jesus Christ, asking for Your divine intervention in the life of our dear sister. You are the Great Physician, and there is no disease that is too hard for You to heal. We ask for Your healing power to manifest in her life, reversing the effects of Retinitis pigmentosa and restoring her sight completely. Lord, we also pray for peace and patience for the family, that they may trust in Your timing and goodness. In Jesus' name, we pray. Amen."
We are also reminded of the blind man that Jesus healed in John 9:1-7 (WEB): "As he passed by, he saw a man blind from birth. His disciples asked him, 'Rabbi, who sinned, this man or his parents, that he was born blind?' Jesus answered, 'Neither this man nor his parents sinned, but that the works of God might be revealed in him. I must work the works of him who sent me while it is day. The night is coming, when no one can work. While I am in the world, I am the light of the world.' When he had said this, he spat on the ground, made mud with the saliva, anointed the blind man's eyes with the mud, and said to him, 'Go, wash in the pool of Siloam' (which means 'Sent'). So he went away, washed, and came back seeing."
Jesus is still the same yesterday, today, and forever (Hebrews 13:8). What He did for the blind man, He can do for your sister. Let us keep praying and believing, for with God, all things are possible (Matthew 19:26).
Lastly, we encourage you to seek God's will in every step of the treatment process. While the cost of treatment in India may seem overwhelming, remember that God can open doors and make a way where there seems to be none. Keep trusting in Him, and do not lean on your own understanding (Proverbs 3:5-6).