When you roll for her "She Keeps Getting Bigger" trait and roll a 1 or 2, she's got Sidestep, Quake, Toughness, and an 11 attack. If you roll a 3 or 4, she's got Sidestep, Toughness, CCE, and an 18 defense. If you roll a 5 or 6, she's got the same powers as if you hadn't rolled at all, but her speed, attack, and defense all drop.

Lower roll, in this case, seems better.

ETA: Sorry, not "if" you roll, "When" you roll. Power doesn't say "may," so it's not optional--if she makes a KO, you're risking that stat drop whether you want to or not.