Losing Louisa

Told from the point of view of a younger sister, this drama depicting the effects of teen pregnancy on a family reveals a keen authorial intelligence, but its weaknesses ultimately outweigh its promise. Caseley (Kisses) deftly introduces a raft of conflicts as she focuses on Lacey, a normal-enough 16-year-old with a steady baby-sitting job, a best friend who wears black lipstick, and a crush on a jerk. Lacey is shocked when she walks in on her older sister Rosie, a classic ""good girl,"" doing ""it"" with her boyfriend; Lacey rolls her eyes when her mom, known for her sharp thinking, turns to jelly as she prepares for dates with her first post-divorce boyfriend. Caseley juggles the various story lines with impressive ease, and some characterizations are superb, the mother's in particular. But when Rosie confides to Lacey that she is pregnant, the novel begins to slip. Lacey and Rosie's relationship feels vague, even as Lacey accompanies Rosie to a family-planning clinic and gets information about abortion, and even after Lacey and Rosie share the intense experience of baby-sitting for their father and stepmother's days-old daughter. Her maternal instincts dramatically awakened by her new half-sister, Rosie announces she is going to keep the baby; a chapter or two later, she decides on an open adoption. It's too cozy and neat a solution for the complex family portrait Caseley has drawn. Ages 12-up. (Mar.)