Also the title of the latest installment in the series being "A Dance With Dragons" might be a clue for readers/watchers early on that a some point there would be dragons.

Also, the dragon art on everything.

Also, that character being from a house that routinely rode dragons.

And those being dragon eggs.

And saying that dragon eggs would hatch in fire.

And her receiving them in one of the first episodes.

....Yeah, no sympathy for someone "spoiled" by that, really.