The write-up said the women were "two Aes Sedai who've been with Rand from the beginning", which eliminates Min (how could she be in a link anyway?).

I thought it was Egwene for a long time, but in the comments, someone who helped Whelan with the cover revealed it was indeed Moiraine. And in the new high res pics, if you zoom in, you can see the keseria in Moiraine's forehead, and the ki'sain in Nynaeve's. So it is definitely those two.