There was a scene in episode 9 or 10 where she went to Datak for help escaping Defiance, and he dumped her in that wasteland so she could hide from the law. The admission of her building the fake Kenya was some episodes earlier, where through flashbacks we learned that she and Niles put the Ego bug into Amanda's head (the one that made her crazy a few episodes earlier) to extract her memories and then place them into the Kenya clone to make her somewhat believable.
Niles had a brilliant plan to reunite Amanda with her sister as a way to make Amanda so grateful that Niles could get into her pants, but it didn't work out when the base got breached before they could finish growing the Kenya clone, and then the invaders thought she was the real Kenya and would thus make a good hostage, which prompted the Kenya rescue episode.
Wow... I quite like this show, but when you recap it like that it makes the whole thing sound really dumb