LOS ANGELES (Reuters) – Actress Bonnie Franklin, who starred as the harried single mother of two teenage girls on the 1970s and '80s television comedy "One Day at a Time," is being treated for pancreatic cancer, her family said in a statement on Monday. Franklin, 68, a petite redhead, is best known for her role as divorcee Ann Romano on the show, which debuted in December 1975 and ran for nine seasons on CBS. It co-starred Valerie Bertinelli and Mackenzie Phillips as her two head-strong daughters. …