My dog is a rescue. She has a very skittish, submissive personality--she gets scared by things fairly easily, but usually I can at least figure out why. But recently she has been avoiding coming into the living room towards the outside wall (I am in a small above ground apartment). I'm gone all day at work, and if I had to guess why she is all of a sudden scared, it would be because a bird flew into the window, or maintenance maybe was doing some work on the roof against that wall. It's unclear exactly what she's scared of, but she hesitates when coming into the room, looking in the general direction of the windows/wall (not always in the exact same spot), and then decides to turn around and run back into the bedroom.
What is the best way to get her to go back to not having a fear of the wall?