With so many juvenile novels jampacked with improbable plots, it's refreshing to come across a book that is simply a leisurely, often perceptive look at a family in the painful throes of change. At first glance, the Redmond kids seem to have it made: 13-year-old Taylor, a dedicated bird watcher, and her younger brother Jem, a fanatic fish collector, have free run of their Florida island home; their baby brother B.J. isn't too much of a pain; and while their parents quarrel often--over Junie's obsessive antique buying and over Tony's obsolete male-chauvinist mentality--they obviously care for each other. Yet soon there's more and more fighting and less and less making up until Junie, an insistently immature ""free spirit,"" decides to split because she needs more ""space."" Taylor's growing awareness that grownups are often foolish and unlovable--it's what her best friend Sandy has been telling her for years--certainly seems a fair enough assessment. But even if you don't agree with Stolz' downbeat and sometimes overstated message, her full-blooded characters and slow, easy style (very much in keeping with her languid, lush locale) are more than enough of a bait.