CHELMSFORD, MA—Based on her above- average height, the presence of two functional arms, and the near certainty that she was a student enrolled at a junior high school, it was suggested by a family friend Tuesday that 13-year-old Hannah Jeffers try out for her school's basketball team. "Wow, you've really grown," neighbor Tom Pike told Jeffers at a recent neighborhood cookout. "Ever play basketball? You should." When Jeffers expressed ambivalence about the idea, Pike cited the same physical and demographic characteristics in proposing she try volleyball.