Sarah appears to be a 7 year old girl. She's not. She appears to have wayfinder abilities and she dines entirely on raw meat. She wants to eat people but she's not allowed.

Sarah works for Knight Commander Ravensfall, and will occasionally be lent out to groups assisting the Broken Wing that require a Wayfinder guide. It's probably preferable to cough up the money for a Guild Wayfinder really.