Katharine McPhee, 36, steps out three weeks after welcoming baby

Katharine McPhee steps out for the first time since welcoming a son with David Foster

Katharine McPhee flashes peace sign as she cradles newborn son and her Chihuahua in Instagram snap

LeAnn Rimes and Katharine McPhee Have a 'Coyote Ugly' Moment in 'Country Comfort' First Look (Exclusive)