Prim, passive-aggressive, waspy - Betty is back in Mad Men January Jones, however, is remaining tight-lipped. Jones, 34, plays Betty Francis (formerly Draper), the young suburban mother-of-three in meltdown. And apart from the observation that we'll be seeing her character's dress sense change - "less petticoats, different silhouettes" - she is maintaining a dignified silence on all plot points, of which her prim, passive-aggressive alter-ego would be proud. But there, I soon discover, the similarities between the two women end. I remember at the end of season two, when Betty had a random affair with a guy she met in a bar, and the reaction I had to that, from fans. They would all say: "How could she have an affair? How could she do that to Don? I just thought: "Do you watch the show?" The guy has been sleeping with so many other women; Betty finally gets hers, in a bar, and people are, like, "What?!"" Perhaps, I point out, we haven't actually travelled as far from the sexism of the 1960s as we'd like to think. I meet Jones in a genteel hotel in Los Angeles, where the show, though set on New York's Madison Avenue, is filmed. While Betty's ladylike fashions are heavily influenced by Grace Kelly, Jones herself - a tall, slim, Hitchcock blonde-style beauty - has a more contemporary style, clad today in black leggings, black riding boots and a satin shirt, with faint traces of pink streaks in her hair. She is also infinitely more modern, not to mention enthusiastic, in her approach to parenting; she is a single mother to seven-month-old Xander Dane, and has never publicly revealed who her son's father is. While Weiner worked around Jones's pregnancy as far as storylines were concerned, "I still had to go back to work when my son was six weeks old, and that was a little difficult," she admits, albeit uncomplainingly. I brought him to the set though, so I was still able to nurse, and I could see him and squeeze him when I missed him, which was often. Jones may defend the often brutal Betty, but she also admits: "I have learnt nothing from her in the mothering department. I don't think Betty sees the fun in it. She sees it as a burden and an inconvenience. While Betty is waspy and well-bred, Jones herself was brought up in rural South Dakota, one of three sisters, but like her on-screen character, spent time working as a model, after being scouted while out shopping. She moved to New York aged 18 - the second time she had ever been on an aeroplane - where commercials eventually led into acting. After a decade of playing bit parts for blondes, including tiny roles in two Richard Curtis films, Love Actually and The Boat that Rocked, landing the role of Betty has brought Jones success, and larger roles in films such as X-Men: First Class. Unusually, though, Jones is approached less in public now, she says. "People used to come up to me much more when Betty held her emotions in, was a little more sympathetic and you pitied her more," she shrugs. Now, I think people are actually scared of Betty, and are shielding their children from me in the street. "Mad Men" season five begins on Sky Atlantic on Tuesday, March 27 at 9.00pm