I ordered at L/XL and it fits my 80 pound 11 year old.  There is no way it would fit even a medium adult woman and certainly not a large one.  I would say only get this is if you are very small, and small chested too.  Very disappointed because it is such a beautiful sundress.  Possibly mine was mislabeled because it doesn't appear to be a problem reading some of these other reviews.  I will have to return it.