To me, it sounds like you'd rather not have her there. If that's really the case, tell her that. It can be done nicely, but it needs to be done.
Tell her straight out that her comments and advice, while well intentioned are negative and hurtful and you don't want to hear anything negative in the days preceeding or following your wedding. Also tell her that her behavior after she's had a few is abrasive and confrontational, and that you are concerned that at an all inclusive resort, she's going to be tempted and do something to embarass herself in front of your guests.
Are there others (siblings, your dad, aunts, uncles, etc - NOT YOUR FI) that you can enlist to help deliver the weight of this message? That may also make the message more meaningful. Worst case, even if she does come, maybe she'll think twice about things and stick with sodas...
I wish you the best of luck and will keep my fingers crossed for you!!