I was curious about this to on some products where there's 'one size fits most' and a 'plus size' option. I think I'm just going to order one sometime and find out. You might have some luck looking at some of the reviews for those types of items.
From my experience Dream Girl's plus size and one size are usually nice. The Plus size usually fits actual plus size. And the girls who are on the lower end of plus size usually get away with the one size fits all. Plus size for dream girl can be found on the size chart. If you take your measurements you will know what to order.