She tries to visualise the keep, to see if there was a straightforward way that sections of it could be partitioned and quarantined off if needed, but only succeeds in confusing herself.

"It's a good idea. Perhaps we could liaise with the other healers and a set of blueprints, and plan in advance of whatever illness is thrown at us next." Not that she expects Skyhold to have an exact set of blueprints, but she's certain that the scouts must have a fairly accurate plan of the place by now.