Okay, not really. But Underground Online wrote a hilarious list about who they think should be Supergirl, who is going to show up on the seventh season of Smallville.

Number Three on the list? Mary-Kate and Ashley Olsen!
Underground Online writes
The Olsen twins could take on Supergirl for some super stunt casting. They’re young, frequently blonde, and passably cute in a little monkey kind of way. They could pull a Michelle Tanner and split the role – one taking a scene while the other studies, or naps, or… whatever an Olsen twin does. Plus, even though we hear Supergirl won’t be flying in Smallville, they might reconsider with an Olsen twin on board. They’re so light, they might actually lift off without any special effects whatsoever.
I think it would be hilarious. I also think their top two picks — Hayden Patteniere of Heroes and Kristen Bell of Veronica Mars — are better choices.
However, I’d never be against Mary-Kate and Ashley being cast!

Mary Kate and Ashley as Supergirl… hmmm, I don’t know about that; they might be too expensive coz you’re paying twice. But – they might do well for the Justice League’s SuperTwins ! – “supertwins, activate!”
lol, good call Grace! Who can we pitch that too?