First, it was a club. Someone would put out the, “Sisters! Sisters! Sisters!” call (usually Phoebe, so it was more like, “SIT-TAH! SIT-TAH! SIT-TAH!”) and they’d come from all directions to converge behind the recliner with a lamp where they’d do cheers about being sisters and play Rock, Paper, Scissors wherein the loser was forced to retrieve popsicles from the freezer. Then they’d eat the popsicles.
Before long, they grew weary of chants and fingerplays. (But not the popsicles.) They felt called to do more. So, they assigned each other costumes and special powers to become The Super Sisters.
The Super Sisters fight crime. It’s imaginary crime, but they’re very serious about it. They even pulled the stickers off the Barbie Jeep and replaced them with glitter glue S’s so they’d have “like a Batmobile for Super Sisters.”
The Super Sisters say, “Shut up, crime!” (Not really. But The Crimson Bolt says it in the movie Super that’s totally not for kids, but also totally awesome. You should watch it.) The Super Sisters actually don’t say much about crime. They simply fight it. Cutely.