May be not unfriend her, which might be difficult to recover from, but gently put some distance by explaining about your perspective?
Although, I know very little about her personality and how she would respond to your sincere concern. There are some people, no matter how gently you present your perspective, still get offended. So, in summary I don’t know her and it is understandable if you are trying to avoid getting into conflict with her.
On the other hand, it sounds like she needs to be reminded about being a little bit more self aware. If she always follows her mind and discards the advice given....
i would want my friends to tell me if I am losing my self awareness and as a result hurting my closed ones.
Hope i am making sense.
I usually text the following if I am irritated by a close friend (which is rare but happens): ‘Sorry, dealing with my own drama at the moment. I ll get back with you when my head is at a more clear place.’