She will usually be located indoors, and will be surrounded by a large number of throwable fake books.
This bookish trader talks about how she's selling valuable rare books.
"Please don't mess with the display books! They're fake, I put them down to confuse book thieves."
P.L.Plarken's Map Atlas (15 food): Gives every member of the party the Explorer perk
The Ultmate guide to dogs (15 food): Gives every member of the party the Friend Of Dog perk
The Handyman's Bible (5 food): increases the mechanical skill of every party member by one