Laura Barton: Last Thursday saw the death of Mary Hayley Bell, 94-year-old actor, writer and widow of Sir John Mills. She had been suffering from Alzheimer's, but the cause of her death has not yet been given. Many might speculate, however, that her death owed less to her physical frailty than to the fact that Sir John, to whom she had been married for over 60 years, died in April.