It is in Chapter 18 that the Receiver tells Jonas the story of what happened to the previous person selected to be the new Receiver. Up until now, her story has been a big mystery. All we know is that it ended very badly. The Giver tells Jonas that her name was Rosemary. When he began to transmit bad memories to her she was not able to take the pain and realisation of these strange emotions and sights. She insisted, however, that the Giver continued to transmit bad memories to her until, one day, after a particularly difficult session, Rosemary got up and went directly to the Chief Elder to demand that she be released. The Receiver goes on to tell Jonas later that she asked to inject herself when she was released. She was not able to accept the existence of emotions and pain, fear and loneliness, which had been eradicated by the Community.
Rosemary was the reciver who was selected 10 years aga, same as jonas. she trained with the giver for five weeks, until she coudn't handle the pain, which is why she went to the cheif of elder and asked to be released,by injecting herself. Later in the story the giver tells jonas that rosemary was his daughter, (not it a very clear way) and he wants to be with her.