Quote: I HAVE to photograph a wedding most likely for almost free.
You HAVE to?
First of all, if you go changing how you work your pictures just for this wedding, it's going to throw you off. How are you now with exposures in jpeg? If you can get well exposed pictures the way you shoot now, don't try to change it, shoot the way you know.
I would find out exactly what the bride is looking for and do what you can to get what she is looking for. Please stress to her that you aren't a pro at this and the pictures may reflect that (not a dig at you). Since it's a very small affair, you should have some flexibility as far as setting them up so that you have good angles to shoot from.
Additionally, don't try to change your shooting style for the wedding. You know how you work best, and presumably the bride has seen samples of your work.