I find that military spouses are often overly critical of their peers when evaluating their peers, so there are very mixed reviews about Sarah's writing.
Personally, I find her work to be refreshing because it comes from her. When I first started reading this book I couldn't help thinking, "Well, I cannot relate to this at ALL!" and I threw the book off to the side and forgot about it. But then, I started to realize that Sarah is writing about Sarah, not me. So, I looked at the book as I might one of Sophie Kinsella's (Shopaholic Series) or any other chick lit writer and I loved the book.
Ironically, now I actually know and work with Sarah and find her to be an amazingly thoughtful person. She is candidly funny and that permeates her work, so the read is quite easy and exciting. I don't think her work needs to be limited to 'just' military wives. I think anyone who likes a sense of humor would enjoy Sarah's writing.