Nancy Lu was originally a member of a rival basketball team playing against May "Mayday" Parker's team. May (secretly Spider-Girl) was shocked when her team lost, as it seemed weird things were happening during the game. The ball seemed to move on its own during crucial plays. May's spider-sense kept buzzing whenever she got near Nancy, and curious to know more, she followed Nancy as Spider-Girl. While following Nancy, she observed the girl moving objects without touching them. Spider-Girl confronted Nancy, who admitted that she was a mutant with low-level telekinetic powers. Spider-Girl informed Nancy that she hoped that Nancy wasn't using her powers for her own personal gain. Nancy felt bad, and quit her basketball team. Spider-Girl realized that she was guilty of cheating as well, as she had used her spider-like powers during games, and quit her team too.
Nancy later transferred to May's high school, and began dating May's crush, Jack Jameson. At first, May was jealous of Nancy, but the two soon became friends, despite a few misunderstandings. But when Nancy accidentally used her telekinesis in public, she exposed herself as a mutant. Later that night, several students tried to vandalize Nancy's house, to make her leave town. Spider-Girl intervened, and learned that the leader of the vandals was Brad Miller himself, and was shocked by his racism towards mutants. But when Jubilee offered Nancy a place with the X-People (a new incarnation of the X-Men), Nancy accepted.
When a science-whiz used a magnetic harness to impersonate Magneto, Spider-Girl tried to stop him, and met Nancy again, this time using the costume and identity of Push. Push admitted that she was still in training, but offered her help. Push's telekinesis had grown to the point where she was able to move much larger objects than before, and was able to short-circuit the Magneto imposter's harness when she hurled all of his metal projectiles back at him, then she and Spider-Girl used their respective powers to rip his harness apart. Push found out that Jubilee was angry at her going solo, and Spider-Girl had her A-Next reserve status revoked (as she was instructed by team leader Mainframe not to engage "Magneto" without back-up). But the two girls still felt that their actions were warranted, as the imposter was only a kid, and could have been hurt in an all out brawl. Push is still undergoing training with the X-People.
Telekinesis: Nancy has the mutant power of telekinesis, an ability that enables her to move, lift, or control solid objects with her thoughts. Her abilities are still currently developing. At first she could only move small objects, but Push can now move objects as large as filing cabinets or heavy metal mailboxes. When she is angry, her powers increase, and can move fairly large objects with incredible speed. Push is even capable of using her powers to lift herself into the air, and fly fast enough to keep up with Spider-Girl when she's web-swinging.
Nancy is a capable basket-ball player.