On Tuesday January Jones was spotted running errands with her adorable son Xander, and we can't believe how tiny she is!

Mad Men has already started shooting its 6th season, so we have to wonder if January will be putting on a few pounds to resume her role as Betty Draper. The actress famously dropped two dresses sizes when she starred in X-Men: First Class back in 2011, and since giving birth a little over a year ago, she's lost all the baby weight ... and then some!

Still no word on who Xander's daddy is, but after looking at this photo, how can you NOT speculate that it's Jason Sudeikis?