One thing about Corcoran's novels, they certainly keep you on the go. This time she jets us along with her 16-year-old heroine to Palm Springs. There Rachel Douglas vacations with Grandad and Grandma Kelly while back home her parents--dithery, spoiled smother-mother and workaholic dad--decide to call it quits. At the Trianon Apartment Motel (a tiny, rundown Grossinger's West), Rachel swims in the heated pool, loads up on Grandma's good cooking, and kibbutzes with the ""over sixties"" set (""You're a good kid. For a goya,"" says the yenta-in-residence). For companionship this side of retirement age, she finds pseudo-sophisticate Ariadne and her super-brainy younger brother who are staying at a tonier motel and struggling with their own more precipitous parental problems--an abusive (now dead) father, a playboy stepfather who's only interested in his Porsche, and an ex-starlet mother whose far from benign neglect triggers Ariadne's suicide attempt. It's this last off-camera turn of events that brings about responsible Rachel's own hour of decision. She abandons her plan of permanently living with her grandparents and resigns herself to returning home to ""take care"" of her divorcing mother. At 115 pages, this sometimes seems more a sketch than a full-bodied book, and some of the characterizations are too broad (the Trianon ladies, for instance, seem cloned from Mollie Goldberg). Still there is a lot of sensible home truth here, of the sort that gives Corcoran's books (to quote a Trianon guest) such ""gemÃœtlich"" appeal.