Why is my ex still checking up on me?

So we broke up almost a month ago and haven't talked for about a week and half and yesterday she texted me and asked how I was and said that she just wanted to check in on me. She also asked one of my co workers if I was working at the place I was working now (they go to school together) she's been seeing somebody else for a couple weeks now but I don't think they're officially dating so I don't really know what to think of this.