They were the moms every kid of that generation longed for...They were the fantasy moms of 1950s sitcoms. Margaret Anderson of "Father Knows Best" (played by Jane Wyatt). Donna Stone of "The Donna Reed Show." Harriet Nelson in the TV version of her real-life self on "The Adventures of Ozzie & Harriet." But towering above them all was Barbara Billingsley. At her death at age 94, she remained so for millions of "Leave It to Beaver" fans, as well as remaining their own mom, too, in some TV-generated alternative universe.