By Emilia Randall The nine-year-old brother of a little girl who died after she was trapped in a sand hole will ”always be a little different” after he was pulled out of the sand and his sister reached for his hand. Sloan Mattingly, 7, and her brother Maddox, were enjoying a family getaway on the beach at Lauderdale-by-the-Sea in Florida when the tragedy struck in February. Now, their grieving parents, from Indiana, have told Good Morning America their son and his sister were each others’ “built-in best friends,” even though he is now an only child “just all of a sudden.” Therese Mattingly …