Long before mothers were blogging about their daily lives, Erma Bombeck’s syndicated newspaper column — “At Wit’s End” — acquired a legion of faithful followers by mixing her musings about marriage and motherhood with healthy doses of humor. Born and raised in Dayton, Erma certainly knew her subject. She and her husband, Bill, had three school-age children when, at age 37, she began writing the column on a makeshift desk in a bedroom of her suburban Centerville home.