See, you brushed it off just like the film does...but how does he dream her before he meets her? The options he's given at Rekall are nowhere near specific enough to design her so perfectly. The novelization sneaks in an excuse for this one by having Quaid ask Melina about Rekall. She tells him she used to model for them.
So, your dreams are only cast by people you've actually met? I'm going on the premise the events of the movie (the Arnold one) are a dream. He modeled the woman for his "ego trip" dream after the woman from his actual
dreams. Sure the information he gives Rekall isn't really enough to model the woman perfectly but that's hand-waved away in just saying that it would have been tedious for him to sit there talking to the woman for 45 minutes specifically designing the woman.
For the record though, if the white-out at the end of the film is to be taken as the "dream" coming to an end, it can't be Quaid waking up. It has to be his lobotomy. (If it's a dream, Dr Edgemar is telling the truth, so we have to take all his dialogue as truth surely?)
But it's my theory the Dr. Edgemar scene was part
of the "narrative" of the dream. He's supposed
to not believe him, or his "wife", and shoot him.