FWIW, I am aware of pre-Medieval veneration the Virgin. What I am more interested in is if there was a substantial increase in the Medieval period that would have given credibility, even if only in the West, to these sorts of claims. The claims generally pointed to the substantial growth of Virgin-dedicated shrines and pilgrimage, and Marian doctrines and apparitions that began to boom in the 12th centuries and onward (e.g. Immaculate Conception doctrine and apparitions, scapulars, etc.). They also claim a growth in the Theotokos' presence in liturgical texts.
I suppose it is possible that the replies so far could be true, and the above points likewise be true. After all, the mere existence of pre-Medieval veneration is not denied by these claims, but only the degree (in the West). That said, this might not be the right forum for this question since it would require someone to be familiar with Medieval Catholic hymnography, spirituality, etc. and not just pre-Medieval.