I think she's protecting herself, because now she understands how ridiculous the zombie idea is--she doesn't want to admit that this was part of her own religious beliefs.
Or maybe Woods directed her not to talk about zombies, because that would open a window for Prior to further destroy her in cross?
It's interesting that she does seem to be carefully choosing her words and holding things back. I thought it was to protect herself, but then she admitted she lied to the police, so...
I am on tenterhooks waiting to hear this call. The fact that she thought to record a call, without police asking her to, is pretty incredible.