In her autobiography Sarah says she'd asked to accompany Andrew on his postings and live in Navy housing so they could be together but her request was denied. When Prince Philip was in the Navy, Princess Elizabeth accompanied him for long stretches, even leaving her children behind in England while she was with her husband. It's interesting that although it was OK for the heir to the throne, whose father was not in good health, was allowed to do that but the wife of a younger son was not.