Willowy, with an airy frame, but capable of projecting toughness as well as tightly-wound characters, Barbara Babcock was a "working actress" for two decades before a recurring guest role on "Hill Street Blues" in the early 1980s turned her into a TV star. On "Hill Street", Babcock was tough Grace Gardner, hounding Sgt. Esterhaus (Michael Conrad) until she had him. "Tough" seems to be a word threaded through Babcock's personal life as well. The daughter of the US Army General, she was raised in Tokyo and spoke Japanese before English. On screen, Babcock seems very much the "lady". Her early