Sullivan persuaded her to change her name to Millington, splashed her throughout his magazine titles including Playbirds and Whitehouse and got her working behind the counter of one of his sex shops. She became a sexual phenomenon virtually overnight and the fan mail flooded in. However, it was her role as a saucy nurse in David Sullivan's 1977 movie Come Play with Me which really made Mary a huge star. Despite appearing only briefly on screen, it was canny marketing within the pages of Sullivan's publications that sold the movie throughout Britain. Within the space of just two years Mary became the most profitable name at the British box office with a string of record-breaking X-rated sex movies like The Playbirds (1978) and Queen of the Blues (1979). But with fame also came unhappiness.
Police continually raided her sex shop and Mary repeatedly complained of police threats and harassment. After the death of her mother, Mary sank into depression which manifested itself in kleptomania and drug abuse. After being arrested for a second time for shoplifting on August 18th 1979, the police informed her that it was highly likely that she would be sent to Holloway jail. A court appearance for the earlier offence had already been set for the following Tuesday. Robert Maxted collected an exhausted Mary from Banstead police station and on returning to their beautiful home in Walton-on-the-Hill he persuaded his wife to have an early night. For the past six months they had both slept in separate bedrooms. Late that evening Mary made one last desperate phone-call to her old 'friend' John M. East, who dismissed her worries. Mary rang off abruptly and on the morning of 19th August her husband found her dead in her bed. The cause of death was a cocktail of paracetamol and alcohol. In a rambling suicide note to David Sullivan she wrote: 'The police have framed me yet again. They frighten me so much. I can't face the thought of prison.' She was just 33 years old.