I'm familiar with hallucinations and introjects.
These hallucinations have been affecting me too, from the inside out if that makes sense.
This makes sense. I had a similar thing last night. A little was triggered, and I kept feeling like someone was watching me or rushing at me. Anyway, I told her that I would deal with it when my IRL kids went to bed, and found out about a memory of why I was feeling paranoid.
I'm not sure if I found a new mother introject, as this was how some of my father introjects appeared, but it's okay. (Others had a more overt hallucination first appearance). Introjects have a bit of a rap, but after awhile, one develops an effective system to deal with them and disarm the scary behavior. Like it becomes second nature, and introjects loose that scariness.
With my system, hallucinations were more like a projection of my internal world onto the external world. Also, what is a hallucination to me, was happening to a little....it wasn't real to me, so I am able to keep my reality checking intact, but to the little it was terrifying. It's kinda odd feeling several things at once, myself, the little(s), and the introject(at times).
I think it's important to find out from Freya what she thinks.....Does it feel like more of a "shadow" memory? Or is it more like reliving something? Or like reacting?
All the best.