Calyia Stringer had a smile on her face the day she posed for a photo with a yellow flower in her hand. The toddler beamed with pride as she showed off the bloom before handing it to her godmother, Jatoria Foster. “She was so happy,” Foster said. “That was one of the best memories I have of her.” No one thought the same image would end up on the lid of Calyia’s casket — until the unthinkable happened. The 3-year-old was killed last September when a stray bullet tore through her grandmother’s bedroom in East St. Louis, Illinois. For Calyia’s funeral, her family wanted to remember the happiest m…