An author of both novels and picture books (The Purple Coat, 1986) tells an episodic story with the flavor of autobiography. When Katie is seven, her father goes off to WW II. In the lonely time that follows, her mother's pregnant friend Louise, whose husband is also away, comes to stay in the living room of their apartment on N.Y.C.'s Upper West Side; after Rosie's birth, Katie generously gives the two her own room. Rosie's dad returns, but Katie's is killed; after the war, Katie and her mother set off for Texas, where they will start a new life with Louise's nice brother. Though there's little drama here (with the exception of Katie helping Louise get to the hospital during a post-Passover blizzard), Hest presents a warm, evocative picture of the period and of events, both difficult and rewarding, that help Katie learn that ``Love is risky, but...It's worth it.'' A quiet but appealing early chapter book. (Fiction. 7-10)*justify no*