Katharine McPhee is positively glowing! Three weeks after the American Idolalum, 36, welcomed her first child with husband David Foster, 71, she took to Instagram to share a photo of herself in a green silk dress for St Patrick’s Day. Katharine simply captioned the post with a four leaf clover, as she rocked the long-sleeved satin midi dress, which featured a high slit up one leg. The brunette beauty paired the ‘fit with nude pumps and a matching, green face mask.