The Blanketfort (crying and throwing up) - The Official Solas Thread [Spoilers]

There is a moment between Morrigan and Inky when both of them speculate between one another that they went to Temple Of Mythal and absorbed the Well, because Flemythal orchestrated it all. Granted, we (or they) didn't yet know about orb belonging to Solas, but that still doesn't change the fact that we ended up in ToM, because Corypheus was convinced - by the orb, apparently - that it's the last place where he can find something to aid him in his quest for godhood.

Now, Cory seems one of those people who, probably under influence of the Blight, who seemed so convinced of his power and mastery of it that he seemed to ignore a terrible lot about the risk of playing with unknown powers. So it's possible that he couldn't have known whether the information he accessed through whatever means was available to him came from someone who wanted to nudge him in one direction or another (personally I believe it wasn't just Mythal who potentially whispered to his ear...)

It still seems quite a bit convoluted, given all the cosmic coincidences that happened along the way that had unraveled a lot of Solas's plans, for example, but we don't yet know what powers Mythal had access to - and it's not impossible that she has access to powers that has power to predict events in some way OR steer fate, in more or less literal sense (if Fade is domain of the will, then self-fulfilling prophecies could be even easier to make happen).

We do know that there are characters in DA who can prophesize things - Sandal seemingly being one of them. And he was complaining that he is visited in his dreams by a 'scary lady'... it's probably not that hard to guess who that could be. What's more, OGB Kieran also mentions something that may happen in the future (Morrigan being inheritor awaiting new age) and he also mentions dreams in conversation with Flemythal.