Please, forgive me for being blunt, but there is no way I can sugarcoat it. What she did was both unethical and illegal. She may be super sweet as a person and she may have best intentions at heart but that has no relevance to how her actions are qualified from the perspective of the professional code.

She breached the deceased patient confidentiality and that's illegal. The privilege to disclose confidential patient information doesn't die when the patient dies. While the patient is alive, he or she holds the privilege. When he of she passes away, the immediate family members hold the privilege. She has no right to disclose anything about any particular patient to anyone without the patient's written permission, or the patient's family's written permission in case when the patient is deceased, let alone discuss it on social media or any public forum! It doesn't matter that she didn't identify the patient by the name. If the patient's relatives find her post, they will have a good case for suing her or for reporting her to the board.

Confusing you about the parameters of her relationship with you is unethical. She can't go back and forth with "friending" and "unfriending" thing, but, most importantly, she shouldn't have asked you to "friend" her for any reason in the first place. If she was trying to make a point that your possible suicide would make her sad, she could've just said so in session without bringing other people, deceased or alive, into the equation. That being said, I would doubt that doing so would be clinically sound and/or beneficial to you in any way, but it would not be unethical.

Sorry to tell you, but she screwed up big time.