MARATHON MIRANDA

Miranda can't run a base in phys ed class without getting an asthma attack, but then new friend Phoebe, a dedicated runner, starts her training for a marathon, and brother Alex, an amateur psychologist, congratulates her on giving up her emotional crutch. But Phoebe herself falls to pieces when her parents tell her she's adopted; and meanwhile Margaret, an older woman who is friendly with Miranda, suffers from a jilting until she meets Miranda's grandfather during a family vacation in Vermont. ""What it all boils down to is whether you feel wanted or not,"" Miranda explains to her dog--she herself has felt unwanted during Margaret's earlier romance. That's probably enough to tie all the thin threads together--but the story hasn't the strength of feeling of Winthrop's previous novels.