DONNA DOUGLAS always liked the simple things in life. This is the way she lived as Doris Smith of Baywood, La. Fame and success has not gone to her head. At 20s Donna's smile was appealingly shy; it still is. Winning a number of beauty contests gave her the courage to leave home and seek her fortune in Hollywood. It wasn't an easy decision because she had a young son she would have to leave with her parents. "That was the hardest part," Donna said. "Oh, I knew my baby would be in good hands, but I also knew I'd ache with loneliness for the sight of him." Donna's teenage marriage ended in divorce. Before she became Elly May on The Beverly Hillbillies she worked in some top-rated TV shows.