Consider contacting the school and/or district directly to get the most accurate answer to your question. If the "Stafford" you are referring to is located within the United States (such as Stafford, Kansas; Stafford, Virginia; or Stafford, Texas), you can research local schools in SchoolFinder: http://www.education.com/schoolfinder/
You can also use Google to research the Department of Education website for your new state. They may have statewide policies posted for transfers from out of state.
I'm also including some additional resources below you may find helpful. I hope all goes well with your family's move.