Hmm, she's more a blob of threads really, all people are to Seven.
But beyond that their proooobably simultaneously frayed and frozen simultaneously, with lots of the 'better' threads seemingly snipped off or frayed and leading to dead ends. Oh, and given the extent of Infection, it's incredibly 'twisted'. Probably manifests as some kind of mold growing on her that gives off very, very bad vibes.
While Seven can kinda deduce that Aoife has had a rough past, and has some connection to ice, she doesn't really know more then that. Her hatred for the sight basically means it's only useful for identifying human vs non-human and for general vibes. In the end it's manifestation is coloured by her experiences in the Infy Icefields, so she's more geared towards differentiating say, demons and humans compared to actually divining stuff through threads.
