More and more Miss Lawrence has concerned herself with the problems of old age -- this time she deals exclusively with the over-60's -- a stipulation if you want to rent a small house in the development Homesite where you'll spend five years as described by a widow (she's only 51) who's in charge of the rentals. Everyone seems happy to come there particularly since no children are allowed: the grandparents are all glad to be rid of their babysitting obligations and to feel flee to lead their own lives. There's the occasional difficulty -- two men incompatibly sharing a house; old Mr. Porter's marriage to a girl a third his age; the art class from which, it is rumored, nudes are emerging; etc., etc., although, as always, this is cheerfully and comfortably landscaped from the golf links to the beauty parlor. Still there will be those readers, however loyal, who may find that retreating with honor to the catered protection of Homesite entails peace at a price. . . better yet you should fight with your daughter-in-law.