Hi Margueriteclare,
Oh my, that sounds toxic.
I'm assuming you've already spoken to your school administration about the situation. Better they hear it from you first (rather than your aunt's point of view first). Your school secretary(ies) could certainly screen calls, and say you are not available. You could even request they not pass messages on to you. And I'm guessing you've already spoken to your pastor about it too. S(he) should have the skills to handle the aunt, but they'll be able to understand more if they've got full disclosure and context from you.
As for her posting the terrible things online which you mentioned, I believe you can contact the various social media platforms, explain the problem, and request they take down this kind of harrassment/abuse/slander. I would definitely pursue that avenue. Take away her voice, and it takes away her power.
She is now telling my mom her organs are all shutting down because she can't eat or sleep or work.
How is your mom responding to this? I sincerely hope your mom is strong enough to set those threats aside, and meet them with
silence. Responding to that would be teaching the aunt/sister that the abusive behavior brings desired results, and the abuse will just keep escalating. I could be wrong, but I'm guessing this is what has already happened...
I refuse to give into this manipulation because I feel it will send the wrong message.
Absolutely. Good for you.
My biggest concern is that she will continue to be verbally abusive to my mom and continue to harass me. I am afraid she will be violent toward my mom and stepfather.
Do your mom and stepfather have a "safety plan" in place? What will they do if this person shows up at their door? If they don't yet have a safety plan, you could help them formulate one, provided they are willing. If they are not willing, then you have done all you can by suggesting it.
My mom thinks I am handling this all wrong by going NC with me and my daughter but I feel I have no choice. I cannot handle the threats any more.
I would do exactly what you are doing. You are following your values, which sound like you choose to love and protect your daughter and keep her safe. This is what parents are meant to do. To further support your decision, I would pose this question to you: if this person doing all these terrible and destructive things were not an aunt, would you let that person spend time with your daughter?
Your mom's response is interesting. She says NC, is wrong. What is she basing that on? Has she got a strong rational case to the contrary? Or, is she basing that opinion solely on emotion because this person is her sister? I suspect your mom is emotionally enmeshed with her sister, and perhaps doesn't have the skills to navigate the situation. Does that fit at all, or I am way off base?