The Sundance Scuttlebutt is a newspaper written by Sarah Jane Cabot (Scumble). On her 13th birthday, when her father, Noble Cabot, refused to let her outside or do anything, she decided to begin a newspaper. It is later revealed Noble kept her inside because he was afraid her savvy would endanger others, or worse, herself.
Sarah Jane's savvy being able to convince people of things through writing, she had a success with her papers. Helga the Horrible (her housekeeper), left the house because Sarah Jane wrote to her "Your mothership is here", signaling for her to leave and hop on a nonexistant mothership. Thus her papers were able to convince people of anything, from Gus Neary being a pirate to people being abducted by aliens!
Drawing near the end of the book, Ledger receives a letter from Sarah Jane saying that she will kiss him next time they meet. When they meet, Sarah Jane tells him he shouldn't believe everything he reads. She obviously could convince people of alot with this power, just like Dinah Kale, Ledger's mother.