Is the car owned by the minor sister or by the family, and how should it be dealt with if it is her property, knowing that the purchase price which led to obtaining the raffle coupon was joint money?

The preponderant view is the permissibility of participating in draws, provided that the item is not purchased solely for the competition without need, and that its price is at market value. If the intention is that the coupon is a gift to the orphaned sister, then the car belongs to her, and her guardian should dispose of it in a way that is most beneficial for her. However, if the gift was not intended and the coupon was written in her name simply as a good omen, then the car belongs to whoever owns the money used to purchase the goods.