This is a very cute children's book. Mr. West's half-sister Matilda is orphaned and she comes staying with the family for a while. It looks like Mr West doesn't like her very much, her being "blue" and all. What this means is an entirely unknown concept to his children, but they also anticipate that they won't like her very much either. But then Matilda arrives and neither her skin nor her hair are blue at all, and she turns out very very nice - winning the hearts of the children in no time.