LONDON—Months after announcing her pregnancy in December, the Duchess of Cambridge Kate Middleton stepped out in public Tuesday, displaying her growing baby bump to a throng of excited onlookers. “Three months into her pregnancy, our crew spotted the usually trim duchess exhibiting a budding belly,” Daily Mirror celebrity reporter Stephanie Wood said of the expectant Middleton, who reportedly showed off her ballooning middle after leaving a routine appointment at St. Thomas’ Hospital. “Though the duchess appeared a little fatigued, we can hardly blame her. After all, she’s smiling for two now!” When reached for comment, Middleton appeared overwhelmed by her highly anticipated bundle of joy, saying only, “I can’t believe this is happening,” before royal guards escorted the weary mommy-to-be back to her private quarters at Buckingham Palace.