The Cole's Notes version? Too much locomotive and too little hot chick! You need to get her up on the footboards, or better yet, have her hold the grab-iron and lean out from the locomotive. Either way you need to crop more tightly on the girl and get some fill light from image left.
focus on your model before you take a picture, look at how her pose comes across on camera and how shadows fall on her - look at her left leg, you know its bent but on camera at this angle it doesn't look flattering, sort of looks like she has a very short leg especially with that yellow railing hiding any curves her leg is making. Get me?
LOL jamesdavidbro!! if it were without the model, i'd want it opened up more on the right hand side though. You're right though, looking at it, it is an odd shot for the model to be in n she doesn't add to it - especially snce she is shadowed, makes it look like a snapshot.
Chose what is your subject...the train or the model...and then fill your frame more with them. This looks like a typical vacation snapshot where you ask your kid to go stand beside monument x and take a picture.
I am more than willing to rip a photo to shreds as part of constructive critique. I see nothing at all wrong with this photo. One thing I might have done is crop off the bottom over grown tracks so as to not reveal that it is a retired display but rather let the viewer think it is still in service. This would have required that the model be up on the deck or the camera at ground level. But it is fine as is.