''Babies make strange bedfellows,'' says Becky Rothstein-Rabinowitz, the plump 'n' peppy chef with a Christmas-celebrating Jewish mother-in-law from hell. They sure do, at least in Jennifer Weiner's new novel about four women experiencing motherhood for the first time. In addition to Becky, there's Ayinde, the wife of a superstar basketball player, Kelly, a 26-year-old event planner, and narrator Lia, the guilt-ridden Hollywood starlet who runs home to Philadelphia after her firstborn unexpectedly dies. The quartet bond over a Lifetime season of disasters both natural (post-baby sex lives) and unnatural (a cheating husband). Aside from an overly cinematic happy ending or two, reading Little Earthquakes feels like curling up on a couch with a best girlfriend in crisis.