A Mexican-American child tells her father about her first day in kindergarten—from little Susie, who cried all day (even while she sang ``Good Morning to You''), to stubborn Archie, who climbed a tree and wouldn't come down until the principal climbed up after him (it took the fire department to get the principal down). Margarita's matter-of-fact, child's-eye view of the droll mishaps of an ordinary school-day makes for funny reading. The title comes from a playground taunt: ``Kindergarten babies, born in the gravy!'' Was she really nacida en la salsa? Margarita wants to know. ``No, in Guadalajara!'' her father replies. Charming, but perhaps more for adults than children, who may miss many of the jokes. Sprinkled with Spanish words and phrases that can be figured out from their contexts; illustrated with cartoon-style colored- pencil drawings (with dialogue balloons) that clarify some of the more cryptic portions of Margarita's deadpan account. (Picture book. 7+)