What are some books by Margaret Peterson?

If you were talking about Margaret Peterson Haddix, then:

Running out of Time

the Among the Hidden series

Among the hidden is a great series the best series i have ever read!! Right now i am on the 6th book, Among the enemy. I finsished most of the books in a day or two. The series is Among the hidden, Among the impostors, Among the Betrayed, Among the Barons, Among the brave, Among the enemy and finally Among the Free.