Yes, a blindfold or anything which prevents her from seeing would help. I had thought about it affecting her other senses, but corpses don't make sound, and smell involves particles drifting off it, and she's unlikely to want to taste or touch what she sees. However, in the foundation/institure, they want to test her, want to expose her to as many possible stimuli as possible, to glean what information they can.
I'll modify it, add a paragraph the effect that her eyesight must be protected and unobscured, as even an offhand comment could be a 'prediction'.
Edit: Done. I've added a couple of lines to the beginning (before her abilities are described, hopefully adding a little intrigue to it), outlining why they don't just blindfold her.