This is stretchy fabric. you can Size down. but I choose not to because the medium was going to show my mom pooch and I wasn't comfortable with it. This is not white. It is off white to beige shade. This dress has lining underneath. You can wear as it is or up it with a cool looking belt. The sleeves are bit see through but only through the tiny mesh. I am 5 by 8 inches in height and it covers my butt and cuts off just 2 inches above my kneecap. Pretty modest.