Some poor NPC is wandering around the mountains and gets hit by Purple Lightning, which brings Superwoman/Lucy Lane back to life somehow.
Lucy remembers her life, and feels that she's always been in her sister's shadow, in particular when it comes to a relationship with their father.
Her dad apparently died, so Lucy joined the army, almost as a way of committing suicide. But it turned out she was good at it. And then...
A new uniform, one he wants her to wear. The Superwoman uniform, capable of giving its wearer Kryptonian-like superpowers. So in a way, Amazons Attack gave us Superwoman.