Cassie? Yeah, she does have powers that she doesn’t know about. Kate though? Nope. But neither did Clint or Bobbi. Eli might be looking for excuses to keep the group small, but I think Billy really wants more people to join them.
Young Avengers Vol. 1 #2, pages 20-22. May 2005. Collected in: Young Avengers by Allan Heinberg http://www.amazon.com/dp/0785149074