Zach Galifianakis has also spoken out about Jones' attitude in the past.
We've got some good news for January Jones.
January Jones pregnancy not a surprise, says Mad Men boss.
"No, she's a sweetheart," Slattery said. Reps for Jones and Jared declined to comment for our story.
So it's no wonder January Jones made time for some prenatal yoga yesterday, just hours after she was branded 'unapproachable' by a young Man Men co-star.
January, 33, was yesterday labelled 'so serious' by Jared Gilmore, who stars as Don Draper and Betty Francis' child Bobby in the show, who said her attitude made her unapproachable on set.
Asked if he had any advice for the actor who will be taking over from him when he leaves, Gilmore told TV Guide: 'Be careful around January (Jones).
In May, Zach exposed January as a phoney after she referred to him as 'one of the funniest men in town' during an interview.