Presumably, the first floor or so is standard castle and dungeon fare, right? Fieri, being largely outclassed and unwilling to stray too far from the entrance, won't get to the weird stuff until she has a reliable customer base (i.e. the rest of the party).

Fieri heard of the castle's wealth, popularity, and spectacular ease of looting from someone who has experienced it firsthand, and recognized the mercantile opportunity in the making.