I don't think the author read the series. Elayne and Aviendah became near sister's through the rebirth ceremony in the prologue of Winter's Heart, the eighth book of the series. Just over halfway through. To say that there's no back story as to why they have a strong bond shows their ignorance. They went through a ritual and came out twin sisters according to the Aiel, from the womb too being born thanks to the power. They both move on to become powerful women in their own right, of their own accord. Turning this into a love story missed entirely the importance of them being sisters.

It was the prologue of winters heart, and it wasn't a marriage ceremony, it was a birthing ceremony. They became twin sisters birthed but the what woman who volunteered to go though the birthing pains. I'm confused how the author of this article missed that.