I looked up the size 0 juniors size chart and it says waist size is 25-25 inches these are 27 inches so they may be a bit big. I would measure the person who would wear them.
The inseam is 29 inches so I would measure your favorite pair of Jeans and see what the inseam is then your sure to get a good fit. I would say these are average length. The waist is 27 inches around:)