I don't see why having past world data to piece together blood/soul memories into a coherent virtual experience is so unlikely to you.  But you do insist that the Columns showed her those visions. :D I think they were hallucinations/post-hypnotic suggestions  Well, you are stuck on this notion you've created about single mode, only blood memories, so of course you think this must be hallucinations. :)  First of all, I don't believe that the Columns did show Aviendha a past Turning, I just think that if they showed her ANYTHING, is was the past, read through Blood Inheritance, rather than any sort of actual future.  Second, Blood Inheritance is not necessarily linear. Factors(memories/experiences) diverge and converge so that in one generation they are weak or dilute and in another they are recombined as strong as ever. The recombination of ancestral memories from one or more Turnings in the past is statistically unlikely, but then, so are the "coincidences" that make any of the major characters who they are. I've written elsewhere about "the Pattern's 0,000+ year breeding program" that produced Rand at the right time and place to fight T'G  