In Elric (MRQ2) there is an advanced skill called witch sight, but surely any magic system can provide a method of magic detection.
A little self harm blood sacrifice for blood magic, a commune with ones spirit guide, common magic spells of varying power to determine basic magical aura (perhaps second sight would work for this too) to advanced information , the supernatural senses of a summoned otherworldly creature, a prayer to ones deity (soul sight perhaps?), or for sorcery, mystic vision.
Legend Core rules p201 wrote:
This spell allows the caster to perceive magic, by augmenting his primary senses. It allows him
to see, hear or perhaps even smell spells, enchanted items and even a creature’s Magic Points.
Other than those ideas, I don't think a non magical character should have any chance whatsoever unless they have some special trait or fate regarding the item or type of magic in question. After all it is magic, not something everyone believes in, let alone can perceive, unless of course said item emits an eerie glow/crackles with strangely coloured lightning etc.
To directly answer your question regarding lore use, was the temple of her cult? or a well know adversary of the cult? If so there may be a chance she would be attuned to such a place and detect any magical resonance. Otherwise there isn't any real reason why anything would be detected at all.