The costume looks amazing!  I am 5ft 3in and a size 4 and I ordered a small, which claims to fit up to a size 10 (on packaging).  The costume could certainly be a little larger and if you were any taller than you would probably have difficulty fitting in the costume.  I would encourage you to order a medium if you are a size 6 or larger.  The costume is also 100% poly. so it is fairly warm.  I don't mean to be negative as the costume does look great, the pins were also included along with a guide to how many pins to wear based on the officer.  Hope this helps!