Debra DiBenedetto, a second-grade teacher at San Rafael’s Dixie Elementary School, was fatally struck while riding a bicycle on Monday night in Woodacre. The driver, 24-year-old Paula Drake, a Fairfax resident and waitress, was arrested on DUI allegations. Both she and Ms. DiBenedetto had been traveling west on Sir Francis Drake Boulevard at around 5:30 p.m. when Ms. Drake’s S.U.V. veered onto the right shoulder, striking the bicyclist near Railroad Avenue. Though Ms. DiBenedetto had…