I am also a bridesmaid in 6 weeks time, in Miami!!!
I have 10lb to lose to get to target but only 2 weeks till the final dress fitting. I hope to lose at least 4lb in that time leaving me 6.5lb in the 4 weeks before the wedding. When I had my last dress fitting they said that the body doesn't really change if the lose is less than 7lb, so I should be ok to lose at bit more after the fitting in two weeks and the dress not to be too big.