Susan “Lynn” Cooke of Tampa is relatively new to masters track, having “first stepped on a track when I was 56,” as she once wrote. So she can be excused for not getting the memo that you don’t set records six months before aging up. But Lynn set herself a goal: the W55 American record in the mile. On Sunday, at age 59 1/2, Lynn says she clocked 5:38.3 — taking a sizable chunk off the listed AR of 5:41.71 by Lesley Chaplin Hinz in 2015. (Results from the Robert Walker Jr. Pre Disney Club Championships Relays & Open Tune-up…