It sounds like you're her supervisor.
Sure, she's a good worker, and you want what's best for her as well as for your business.
But you also need to cover your hindquarters (like you did) in case she has a bad incident again in which she or others are injured, say if she had some sort of episode while operating machinery.
Keep precise records, and make sure that you advise her to see her physician according to the doctor's advice, and to make sure she knows that she not only can, but *should* take off if she is unable to continue the day's work.
I for one am skeptical that "panic attacks" are a real medical condition, but that is not for laymen like us to decide here in arfcom GD. Sheesh, if I were to clutch my chest and go into conniptions every time I have to make a major decision at the office...