The American Idol star tells Entertainment Weekly that doing the iconic superhero role would be "a huge mistake," and that she's not going to be some "slutty female" when she poses on the cover of Shape magazine this fall.
The songstress thinks that the prospects for "Wonder Woman" aren't very good, and that the production is in an incredibly early stage anyway.
Wonder what Katharine's high school friend, Rachel Bilson, who is rumored to be in consideration for the role as well, thinks about that!
She hasn't ruled out a photo spread later on if things don't quite work out, however. "If my career's going downhill, then I'll do Maxim or FHM," she jokes.
McPhee, 22, also says that any suggestion that she skipped the first three weeks of the American Idol tour are false, and that her new record will surprise her fans.
"People in the industry are hearing about what I'm doing, and they're really surprised, and I like that," she said.