I would first thank them for giving you this awesome privilege of praying to God on their behalf. It is not wrong or sinful to feel this way. This request is asked of me often when I visit hospitals and nursing homes. We are very human, and for those who believe in eternal life, it would be natural that we would want to go to heaven and be with our loved ones, especially if we are sick and all our loved ones have died. The changes can be very difficult to cope with. However, I also gently remind them that they were given a gift of life. Their life represents so many things (personality, wisdom, life experiences, and prayers) that can be shared with and for others at any age no matter where they may live. Only God Himself knows when you are not needed anymore on this earth. It is His choice to decide when we go to heaven. When I do pray with them, I tell God exactly what they want me to say and then I will add “Thy will be done, Lord. May they be willing to submit to Your will until that day when they will see Your face to face. Amen.” Remember always, that God knows their hearts.