"She is the joy of the whole family."
Translation:Ella es la alegría de toda la familia.
Maybe it's not idiomatic, but I also thought "familia entera" was acceptable.
Because ‘agua’ begins with a stressed ‘a’, but ‘alegría’ begins with an unstressed ‘a’.
I had to choose among 3 answers, two of which were the same as much as I could tell--they were both the same as the above answer. There seems to be an error here.