Is my client being manipulated directly by extraterrestrials? Is that why she is so frantic?

This indeed is the case, and we can commiserate here because you are in between a rock and a hard place—the more information you share with her the more terrified she will become. She knows there is something outside her that is manipulating, and is not satisfied with solely blaming her own mind, although that is contributing as well. At this stage, she has been programmed to do self-tormenting and is part of the picture. Also, the advice to disregard the dire messages is still sound, regardless of their origin. The extraterrestrials are wanting to terrorize her but their threats are a bluff in that they plan no direct assault on her physically, being content to just keep her under attack mentally.