A "bio" from that site:
Peppermint Patty is a pro on the baseball diamond, but in the classroom she's a D-minus all the way. Bold, brash and tomboyish, what she lacks in common sense she makes up for in sincerity. She's the only one who calls Charlie Brown "Chuck." Oblivious to much that goes on around her, for a long time she seemed unaware that "the funny-looking kid who plays shortstop" was a beagle. She has trouble staying awake in class; most of her waking hours in the schoolroom are spent analyzing the probability patterns of true-false tests.