Haven't read this one - but here's the blurb from the back cover:
Jiana, hero for hire, managed to accomplish quite a lot on her last adventure. Indeed more than all of the heroes of Bay-Bay and its boy-prince could manage. But life goes on after the adventure is over and Jiana decides she needs something to give her life direction: she'll take on a new apprentice, and make a perfectly well-adjusted hero out of this one (since her last apprentice fell in with some pretty unsavory company).
But Jiana couldn't pick just anyone: she had to choose a crippled slave girl. And everyone knows you can't free a slave - slaves have to free themselves. So Jiana has a friend sell her into slavery too, so that she can teach this girl how to become a hero from the bottom up.
For her first lesson, Jiana must free herself . . .