Your calling to serve placed you and your family in another culture. This book: Belonging Everywhere and Nowhere: Insights into Counseling the Globally Mobile treats how to work with your children who are a blend of cultures. It is worth reading to help you now or to help you prepare for when your children are grown.
John O’Malley has found this site to be helpful for missionaries: http://www.missionarycare.com/ebook.htm.