Davids Bridal Sizing

I have a question on their sizing:

Is this true that their bridal dresses are cut smaller that the bridemaid dresses...

I am asking b/c normally there is a one size difference between me and my sister, her being a little larger, b/c she is taller. But she just tried on her BM dress, and she is the same size in BM dress as I am in Bridal (i.e. the same #)... The sales person in the store said that the bridemaid dresses are cut normal, but the bridal are cut small, and I just wanted to check if this was true or if I ordered my dress in the wrong size (perhaps I was bloated)?

Thanks