The primary thing I noticed was the bass line was a little bit buried. The alternating-type line like in a country song needs the bass to be every so slightly more prominent in the mix. It doesn't need to be much more than it is but as low as it is now, the song loses its propulsion. My opinion is that the key instrument in this song is the bass and the all fall after that.
The vocals were a bit up front. Not by a lot. I almost get the sense that she is 'on top' of the mic. Ya know...too immediate and the mic/track almost seems to be on the verge of clipping. I'm not convinced but I think that kind of issue might be helped with her slightly less in the mix. Obviously she is the key to the song so I'm not thinking to bury her in the mix but just a little lower to take off the immediacy.
Reality is, it's not a bad mix at all. It's a pretty rock solid mix so the things I mention above are just detail but are things that my ear hears. Otherwise, all the other instrumentation is really well done and mixed. There is a lot going on and a 'simple' country some like usually has lots going on but doesn't seem that way. It's kind of the magic of that type of song.
Very good stuff.