Well that's a nice reversal anyway. It's really hard to tell if they've put on weight in a winter coat. The undercoat puffs out the guard hairs so you can't see a silhouette. Once it warms up there she's bound to drop the weight again, I always think it's the more important that they're slender in the warmer months so they don't get overheated by carrying fat under the fur. Or you could always throw her outside in the deep freeze for a while - dogs burn more calories in the cold.