Like she did most days, 16-year-old Diamond Alvarez walked her family’s dog Peanut in her southwest Houston neighborhood on Tuesday evening. Since it was already dark, her mother, Anna Machado, told her to only stay out 20 minutes and then return home. But Diamond never came back as she was fatally shot around 9:30 p.m. Tuesday a couple of blocks away on the side of a street near a grassy field where all the neighborhood children play. Her family found her body by the greenspace after Peanut ran home without Diamond. Machado tried to revive her daughter by performing CPR, but it was too late. “I tried and I tried and I tried and, and I seen her that it was nothing else I could do, I just started telling her how much I loved her. And ‘I’m always here,'” Machado said. Houston police on Thursday continued looking for who …