From the looks of the pictures, your shoulders look fine to me. I think we all lol at ourselves with thinking we have broad shoulders which in all reality they are only proportionate to the frame we have. Just leave this in mind, we perceive ourselves in the worst way, and others are there as an outside eye to help us know that we are us. You are you, I am I, etc...
All in all, its not necessarily the shoulders so much that we should mind so much as the triceps/biceps area of the arm, if the muscles there, which actually determines which types of clothing can be used to cover that up, if the arms are essentially too big for a girls standpoint, then the clothing types which can be used to cover will be addressed. As well as a workout regime in which include exercises that would pertain to lean muscle sculpting rather than to strength train in a workout, which usually includes more cardio, full body workouts, and when weight lifting using lower weights and higher repetitions, including you will want to get a good stretch before, during and after the workout. The during section is essentially between sets of the exercise you are doing, which would loosen up the muscles as you are working out and so it will lessen the chance that the muscles will tighten up, and shape as a blocky body builder muscles will do so.
Kate <3
