Though fans will enjoy the familiar character, and the story is definitely a common problem faced in expanding families (when the little princess is told about a pending addition to the family, she insists she only wants a sister, no matter how many times she is reminded it may turn out to be a brother), I personally find the little princess to be a bit annoying.  It’s fine, and if you need another new-baby-on-the-way book, it might fill a useful niche, but how many of those does a library really need?