In 2006, Annie Barrows and Sophie Blackall created one of the finest early chapter book series, Ivy and Bean.
Now five years after number 10, Ivy and Bean Take the Case (Chronicle, 2013) comes Book 11. Ivy and Bean, One Big Happy Family, publishing August, 2018.
Entertainment Weekly has the exclusive excerpt here
http://ew.com/books/2018/02/20/ivy-and-bean-one-big-happy-family-book-11-preview/