India, June 26 -- A ctor Kareena Kapoor Khan took to social media on Tuesday to share a heartfelt birthday post for her elder sister, actor Karisma Kapoor. Posting a throwback photo of Karisma (51) with Saif Ali Khan (54, Kareena's husband), she wrote: "This is my most favourite picture of you both... To the strongest and the bestest girl in the universe. It's been a tough year for us. But you know what. as they say, tough times don't last. the toughest sisters do. To my sister, my mother, my best friend. Happy birthday My Lolo." While Kareena didn't directly reference the events, her mention of a "tough year" appears to allude to two recent incidents: the death of Karisma's ex-husband, industrialist Sunjay Kapur, and the knife attack on Saif Ali Khan earlier this year. Sunjay passed away on June 12 after suffering a cardiac arrest while playing polo in London. Earlier this year, on January 16, Saif was stabbed multiple times by an intruder at his Bandra home in the early hours of the morning. He underwent a five-hour surgery at Lilavati Hospital and has since recovered and resumed work. HTC...