It’s been more than 20 years since U.S. District Judge Virginia M. Kendall prosecuted her first child-trafficking case as an assistant U.S. attorney in 1995.In the decades since, Kendall has written numerous scholarly articles on the topic, co-authored two books on child trafficking and child exploitation, gave law school lectures on trafficking traveled to more than 30 countries to teach judges about the issue.Kendall, appointed to the federal district court in 2006, is now working on her third book that deals with …