Well, according to Neo-Traditionalism of Japan, Merry can apparently share what she can see with Renko by covering Renko's eyes with her hands.
So it's not impossible for Merry to share with Renko.
Just hold on for a bit.How come only you get to see the other side of the barrier, Merry? That ain't fair!I wanna see it too! Me too! Pound The Girl I Met in the Bamboo Forest Pound I know! I'll draw a picture of what I saw for you, okay?