Susie was the niece of Lois Lane, and played a number of tricks which Superman had difficulty dealing with.
Susie was Lois Lane's niece. Lois brought the girl some hamsters to take care of, which Superman had rescued from a killer. But Lois began to notice some strange things during her visit. For example, the little girl had made a series of geometrically perfect drawings, and seemed empathically aware of the hamsters' mental state. Later, when Lois took her to a movie, Adam appeared and informed her that she was a member of a post-human race called Neo-Sapiens or Nutants, and he took her away, easily subduing Superman with a telepathic attack when he tried to intervene. ("Superman's New Secret Identity")