Young Maureen shares a lot with her teenage sister, Wendy: the TV, the couch, games, snacks, pranks, jokes, their mom, their busy cartoonist dad, his art supplies, Wendy's clothes, Wendy's friends, Wendy's boyfriend, Wendy's super private diary...wait, what's going on here?! When The Sisters pack their bags to go on a cross-country family vacation to see Mount Rushmore and the Grand Canyon, they find that their best behavior might leave a bit to be desired. Maureen and Wendy hilariously demonstrate the best and worst of having and being a sister.