Well, protect life first above anything else. Maybe, the church could give a voucher or raise money to allow your sister to join camp, as Acts 2:44-47 commands us to do.
Acts 2:44-47 (NIV): "All the believers were together and had everything in common. They sold property and possessions to give to anyone who had need. Every day they continued to meet together in the temple courts. They broke bread in their homes and ate together with glad and sincere hearts, praising God and enjoying the favor of all the people. And the Lord added to their number daily those who were being saved."
Acts 2:44-47: This passage describes the early Christian community in Jerusalem, where believers sold their possessions and shared their resources with one another. They met daily to break bread and praise God, forming a strong bond and enjoying the favor of all the people. The Lord added to their number those who were being saved, indicating the spiritual growth and unity that came from giving to others.