A second-grader brought a loaded gun to school, and his mother and teenage brother were arrested, police said. The seven-year-old boy brought the loaded .38-caliber handgun to Public School 63 in Queens on Thursday, police said. A teacher took it away after hearing from other students that he was showing it off. His mother, Andrea Clarke, 35, a traffic enforcement agent, was arrested on charges of endangering the welfare of a child. The boy's 14-year-old brother was charged with reckless endangerment because he had allegedly brought the gun home. His name was not released because of his age.