Los Angeles : Pop icon Beyonce had a sweet moment on stage with her family. The singer-songwriter invited her mum Tina on stage, alongside her daughters during her Cowboy Carter tour in America. The 43-year-old was performing in Los Angeles when she decided to pay a heartfelt tribute to her mama, reports Mirror.co.uk. Making a special announcement, the Texas Hold Em singer told the crowd, Today is a big day because my mother, who worked so hard on her book, has the Number 1 book on the Ne