Here's something else to ponder. In Silent Hill 3, when you reach Heaven's Night (with a SH2 save game on the card) you find a poster that claims that a Lady Maria is performing on several nights. I bring this up since the MAria we know from SH2 first becomes aware in an appartment above the club with only 1 bullet in the revolver she's holding. Feel free to say "Bah, you're sooooooo wrong" but I think that the town's powers that be may of actually converted this prostitute into the antagonistic Maria that we now know. Using deduction, I also figured that she felt herself changing as well and was going to pull the trigger but it was too late.
ALso, it would explain why MAria complains of being so lonely in the Born upon a wish scenario, since she would have to have memories of being around people in order to notice the lack of them in the town. Also, the memories that were being implanted in her was still underway it would seem as we play as here, since the 2 sets of memories keep on colliding (for exacmple, check the bears out in the mansion's attic and you'll get a message about Laura, a girl the prostitue Maria could never of met, which is why she questions her knowledge of Laura at the time). Pretty wierd, eh?