I've been in 2 relationships that dragged on long past when they should have ended. I regret that they dragged on as long as they did. It was a huge waste of time for both me and my SOs at the time.
I hope I don't sound too cruel, but at this point in life you might want to put more thought into what's best for you and less into what will be best for her unless your personal well-being is a function of her well-being.
You should just do what you think you need to do. Think about how you're going to feel after the exam when you two officially breakup. Do you think you'll regret having dragged on the relationship through step1 studying? Are you going to have regrets that you didn't do as well on your test because you spent extra time on her that could have been spent doing something else? Are you going to regret having broken up with her before step1 because it distracted you?
