My 4th grader does too!
She also loves the Percy Jackson, Magnus Chase and other Rick Riordan books.
Patricia Wrede's Enchanted Forest Chronicles (Dealing with Dragons is the first book).
Raina Telgemeier, Warriors, Harry Potter series.
She loved Half Magic and the Edward Eager books (although she read those in 2nd/3rd grade - if your fourth grader doesn't know them, they're a lot of fun)
DD enjoyed these as well. Along those lines:
Brown Girl Dreaming (DD adored this)
Wollstencraft Detective Agency
Esperanza Rising