I think the idea is that Dany comes to the North.
I am going to reiterate a theory that I had a while ago that is based on one of Quaithe's prophesies.
My theory is that Dany is going to go all the way east, beyond anything we have a map for, and end up on the WEST side of westeros and will actually end up somewhere near or on Bear Island, making that her own version of Dragon Stone, an island from which she will launch her assault on the 7 kingdoms with blood and fire, but she will first take the fight to the White Walkers.
Everything fits with Quaithe's riddle. Bear island is North, Asshai is South. Westeros is west, Asshai is East. to go forward she must go back. From Meereen, she would need to literally go back through Lhazareen, back through the Red Waste, back to Qarth. and the light she needs to touch?
Bran's dream. To touch the light that guards the heart of winter, she needs to pass beneath the shadow.