FOOTPRINTS

FOOTPRINTS Shelby Hearon (Knopf, $21) Hearon's wry, seamlessly woven 14th novel traces how a long-married couple entertain some brutally honest second thoughts about each other, and what -- following the accidental death of their 22-year-old daughter -- having two children really meant in their lives. To the witty narrator, Nan, it meant forgoing her doctorate in paleontology for full-time motherhood, while her mild-mannered husband, Douglas, became a successful ''brain scientist'' at a college in upstate New York. But to Douglas -- always preoccupied with his job -- children signified something deeper than he ever let on. Thanks to Hearon's empathetic, incisive evocation of marriage's safe but often claustrophobic bonds, Nan comes to a new understanding of her husband -- and of the need to develop her own life. A