Why in the hell hasn't she been cast as a superheroine?
Gal Gaddot gets picked as WW over Summer? (personally I'd have wanted Summer for Black Widow or a part of the Whedonverse and Marvel but DC would be just fine)...I wanted a woman closer to 5"10 or Gina Carrano or Carrano-esque. But outside of that, she'd be great for a myriad of characters. Perhaps Supergirl in 2-3 years? Or Ms. Marvel? Batgirl?
Barbara Gordon/Batgirl would probably be my top pick. She'd have to switch to a redhead look but I think she could pull it off. Since Batman is older it wouldn't matter if Batgirl started in her mid-20s-early-30s and has been doing this for a few years alongside the Bat.
Or she could be the new Cat? Both were love-interests to Wayne (Barbara less-so than Selina, though I think that's an interesting love-triangle, though I think we're going to get the Trinity-love-triangle. There has been a alternate-universe version of a child of WW/Superman, which would be very uber, then Batman/WW, still powerful as hell, she could play one of those.)
I just don't get why she's more utilized. My final idea would be for "Fray" the future slayer, or perhaps getting her and Eliza Dushku and James MArsters together for a Faith/Spike mini-series and having her play one of the thousands of new Slayers out there and a very dangerous one that Faith and Spike need to wrangle-in.