Both photos seem to have quite a bit of sunlight coming in from the background (the door and the window) so unless you used +EV (or manual mode), I would think the Autoexposure would underexpose so as not to blow out the window/door. When you processed these, did you have to bring up the brightness/exposure to compensate? If so, this could be the cause of the grain you mentioned.
As for the photos overall, second one is pretty good except the white dress is a bit blown out. The purple came out nice though. Anyway you could recover the dress in CS2 (you did shoot RAW, right?
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