Margaret Dell is 96, but you’d need to check the birth date on her driver’s license to believe it. Sporting a baseball cap with a Harley-Davidson logo on it, she is the designated driver for her seventysomething friends who no longer feel comfortable behind the wheel. Last winter a snowfall threatened to keep her from her appointed automotive rounds. She took a shovel and cleared a path to her car. Driving keeps Dell young. That and knitting. She constantly knits. She makes baby booties and caps and blankets for friends and family whenever a baby arrives–the newborn getting an early blessing from the ageless. And every month, she donates several blankets to a charity for unwed mothers. Driving, knitting … and tennis. She plays two or three times a week. She has a much younger doubles partner who “covers the court. I’m a little afraid to run too much because of the circulation in my legs,” she explains. When she was in her 80s, she played in a doubles tournament that required that the ages of both partners add up to at least 100. Her partner was in his early 20s; they won the tournament. A lifetime nonsmoker and nondrinker, Dell lives alone in a two-story house in Bethesda, Md., her bedroom on the second floor. “I could stay on the first floor, but I try to make myself walk up those stairs and keep going that way.” She buys her own groceries; don’t even ask if you can shop for her. At home she likes a chicken or turkey sandwich for lunch. If she eats at the country club after tennis, she usually finishes only half and saves the rest for dinner.