I thought verso meant to look 'through' and 'she looks through the window' makes much more sense than 'to the window'.
You might be thinking of "attraverso" which does mean through. Substituting "verso" with "attraverso" would indeed make the sentence mean: She looks through the window.
Thank you for the help. I obviously didn't remember correctly. So, does this sentence then mean she looks 'at' the window?
No, it's rather "she looks in the direction of the window"; she looks at the window would be "lei guarda la finestra" (direct object).