Rebecca Barnes is the leader of the Young Allies.
When the Fantastic Four and the Avengers sacrificed their lives to destroy Onslaught, Franklin Richards, the son of the Fantastic Four's Mr. Fantastic and Invisible Woman subconsciously created a pocket universe to save their lives. There they spent an entire year reliving living new lives "reborn" into a reality where they had recently gained their abilities that vaguely mirror how they gained their powers originally.
This new reality was entirely populated with recreations of these heroes old allies and foes, including an entire population of individuals unique to this reality all with their own uniquely manufactured histories. Among them was Rebecca "Rikki" Barnes, who in this reality is the grand daughter of Richard Barnes and Peggy Barnes. Both have had a past relationship with Captain America during World War II, the exact nature of which remains unrevealed, although Captain America did have a wartime side kick named Bucky. Whatever their involvement with Captain America's wartime adventures, Rebecca is seemingly unaware of them. Rebecca would live with her brother John with their grandparents in Philadelphia. The fate of her parents remained unrevealed however it's probable that they are both deceased.
Rikki arrives on the original earth in search of help for her home Counter-Earth that is under siege by the world's version of the Insect Kingdom. She arrives just in time to witness the battle between Araña and friends against the Cult of the Tarantula.
Girl Without A WorldEdit
Now on her own away from her home, she finds that there's no one to turn to. She plans to go see Captain American to only find out that Steve Rogers is dead and in his place is Josiah X. She crosses paths with Araña who takes her to the hospital despite the fact that Rikki wanted no help from her. While at the hospital she is kidnapped by Hydro-Girl and saved by the American Panther. With his help she recovers and sets her plans in motion to go to war against the Insect Kingdom of this earth.
Now using the codename Nomad she leads a new team of Young Allies against Araña and friends. She fights Estrella and when the two earths are fused she fights Araña. Eventually, the two teams put aside their differences to fight the Sisterhood of the Wasp.
Fight For Your FreedomEdit
Nomad comes to Rescue Inc. Tower with the rest of the team to see their new base of operations and home. When Rescue is kidnapped by the Bastards of Evil she goes with the team to find her. In the process she along with the American Panther were confronted by Aftershock and Hydro-Girl. After a fight, she is taken captive by the Bastards as well. While the rest of the team has been thrown in containment cells, she is brought to a room where she is left on a operating table. The whole reason for the Allies being abducted was so that Rikki's brother John could turn her into a mindless weapon for the World Party.