Susan's identical twin sister, Sister Mary Moira, showed up in Salem looking for Susan. John told her that Susan left town awhile ago. Sister Mary was worried about Susan because she had gotten a strange letter saying that Susan had married John and had his baby. John just laughed it off.
Later, Vivian and Ivan became suspicious about Kristen's behavior, not aware that she was actually Susan. Susan told them that Susan had left town, so she didn't need their help any longer. While walking back to her convent, Sister Mary was accosted by Vivian and Ivan, who were convinced that she was Susan. When Sister Mary informed them she was Susan's twin sister, she forced them to perform penance by scrubbing the floors of the convent. In exchange for doing this, Sister Mary promised not to turn them into the police.
Eventually, Susan's attempt to become Kristen unraveled and the truth came out. Susan moved into Marlena's penthouse with John Jr, whose real name is Little Elvis. Susan's sister, Sister Mary Moira demanded that Susan tell her who her baby's father was. Susan finally blurted out that Elvis was the father of her baby.
Susan went to get her brother, Thomas (the third triplet), to help her steal back little Elvis. However, Sister Mary Moira stopped Thomas before he could do anything sinful to Kristen. When Stefano learned what Kristen had done he was outraged and helped John steal back little Elvis and return him to Susan.
Celeste began to see visions of Kristen DiMera being murdered. After she was found sleeping in the park by Sister Mary Moira, Celeste went to St. Monica's convent to rest. Sister Mary told Celeste that something evil was happening to her and she should pray to God to save her soul.
In February of 1998, Kristen DiMera kidnapped and Mary and used her to lure Susan back to Salem. Kristen was believed to have been killed and Susan married Edmund Crumb. Eventually, Sister Mary learned that Susan had been sold into white slavery by Kristen, who had impersonated Susan for months. In the end, Susan and Edmund were reunited and lived happily ever after, while Kristen rots in a dungeon on a far off island.