It's circumstantial, and probably the only real evidence pointing that she's BA, but where was she at the beginning of tGH? Lan says she's off on "her own business" at exactly the same time Ingtar is on his "hunting trip" i.e. at the Darkfriend Social. I don't believe that she's actually a Darkfriend and I don't see RJ having her be the same kind of undercover BA as Verin, but this has always just bugged me.

p.s. My cousin also pointed out that she seems to know very easily and quickly when there are Forsaken in a city, and who they are posing as. I originally dismissed this as RJ just making her the sort of all-knowing mentor figure but idk, now.