I have no dislike for Navani but the text does not giver her any actual foreshadowing for a bondsmith. Other non-Radiants also don't spend a ton of time staring at a perpendicularity, and the fact remains Dalinar not Navani did the work.
Fabrials as we know them did not exist back then, so Navani by default has to be the first.
So no they do not have to be intrested in fabrials, in fact that was never even part of the Siblings consideration, and was a large part of why they didn't want to bond Navani.