Rachel is an Orange Star CO and one of the two main protagonists of the video game Advance Wars: Dual Strike alongside Jake. She is the younger sister of the Orange Star Commander-In-Chief Nell and the commander of the Allied Nations forces stationed in the continent of Omega Land to prevent Black Hole from conquering it.
History
Commanding the Allied Nations forces stationed in Omega Land, Rachel led Allied Nations COs Jake, Max, Sasha, Colin, Grimm, Javier and Jess to stop Black Hole from conquering it. Joining together with and Rachel launch an offensive to liberate Omega Land from Black Hole.
However, Jake and Rachel begin to suspect that something is amiss when the Black Hole Army starts occupying plots of dry land. They eventually learn from defecting Black Hole COs Hawke and Lash that the regime now in charge of Black Hole, the Bolt Guard, plans to drain Omega Land of life in order to give their leader Von Bolt immortality.
Once they've received reinforcements, Rachel's forces defeat a giant Oozium-238 named the Grand Bolt and foil Von Bolt's plans of draining Omega Land to become immortal. Rachel and the other COs then go to confront Von Bolt and Jake (or Hawke, depending on the player's choice) shoots Von Bolt's chair, depriving Von Bolt of his life support system and returning Omega Land back to normal.
With Black Hole defeated and driven from Omega Land, Rachel gathers the Allied Nations COs together and gives a speech thanking each of them for their efforts in stopping the Von Bolt and the Bolt Guard, including Lash and Hawke even though the latter was not present.