I have a plate who I let know clearly that I don't want to make things serious with her, I'm seeing other women and she seemed okay with it (at first). Let's call her Girl A

I have another girl (Girl B) who lives far away and is coming back to spend vacation with me. This girl knows I'm seeing other women too, I tell her to see other men as well so you guys know I'm not lying to anyone here.

Now Girl A asked to see me and I said I will be busy for the next 2 weeks. Girl A then made a clone Instagram account and stalked both me and somehow found Girl B too. She found out I'm spending time with Girl B and started posting vague threatening posts on this account. Something like :"I'm not a good person, I'm very mean. I wonder if I told her about this would she get upset? Would she cry? Be careful who you're messing with"

What would you do with Girl A? I know she's a psychotic bitch that needs to be cut out. I want to know how you would deal with her to minimize risks