Missing sisters is about a little girl named Alive who lives in a orphanage run by nuns. She gets an offer from this family called the Harrissons but she turns them down. She then goes into town after being locked outside to give the all boys orphanage run by churly men the money they needed for a play they were putting on. She meets a nice college boy on the bus. They become nice friends. Later she goes to this camp that all the orphanage girls are allowed to go to since its a holy camp. When she gets there, everyone keeps getting her confused with a girl named Heather. ONe of the other girs from camp give her Heather's name and address since she only lives a few blocks away. She shows up one day and Heather panicks and her mom calls the orphanage. ONe of the nuns come and they talk.
They figured out that they were twins who were seperated at birth. While Alice was getting surgery, Heather got adopted. The girls are told that they can see each other every weekend but that Heather's Family could not adopt them becasue they had 5 and a 6th child coming. At first the girls are upset but they soon get used to it. At the end, Alice gets adopted by a nice family who are willing to take good care of her.