Cool, as for origins/backgrounds... a couple of ideas come to mind.
1) A pilot who ended up gaining her powers trying to get her plane down during a freak storm.
2) an "exchange" hero from Russia, on an UNTIL program. She was once the kid side kick of a Soviet super hero "Red Lightning". Now she has to deal with the biases of many Americans, and her own.
3) A young geologist who was studying Mount Olympia discovered some odd teutonic shifts. By accident, and much to her disbelief, she discovered the Titans were trying to break free below. Figuring if one part of the legend were true, the other must be also... she nearly died climbing to the top of the mountain to warn the Olympians. Zeus rewarded her with lightning of her own, but had Hephastus make her bolts red, so she never forget who is the TRUE lightning flinger.