Who is Varis Lodd from The Last of the Sky Pirates and what is their importance?

Varis Lodd, a librarian knight, rescued Rook when he was a child after his parents were captured by slave-traders. Varis is Felix's sister and the daughter of Fenbrus Lodd, High Librarian. She also serves as the flight instructor to Rook, Magda, Stob and Xanth. Varis wrote a treatise on banderbears, so when she learns that banderbears are being enslaved at the Foundry Glade, she takes Rook and Knuckle there to free the creatures, not knowing it was a trap set up to capture her.