Tina Knowles is coming to her family’s defense. Beyoncé’s mom shared a pointed message via Instagram on Wednesday, March 19, after her grandchildren, Sir and Rumi Carter, were the subject of a social media tirade by Kanye West. (Beyoncé and husband Jay-Z also share 13-year-old daughter Blue Ivy.) “Corny joke, time! ❤️ it’s hard to…
