Thirteen residents from Lexington will walk up to 26.2 miles along the Boston Marathon course on Sept. 25 during the Boston Marathon Jimmy Fund Walk, which raises the most money of any single-day walk in the nation.Lexington residents include Carrie Baker, Carol Cashion, Helen Chan, Julia Kew, Christina Kew, Alex Kew, Larry Munini, Susan Novicki, Karen Ossen, Matt Ossen, Jennifer Roy, Carol Savage and Mandana Sheybani, who will join 9,000 expected participants in the annual event.