? Those are not juniors sizes... juniors is 3, 5, 7, 9, 11 etc. A 3/5 is small, a 7/9 is medium and an 11/13 is large, etc. Some store like american eagle maybe size things a little differently. 7/8 is little girls medium, 10/12 is little girls large and 14/16 is little girls XL. My duaghter is 5 and she wears a 6X or 7/8. I wear a juniors medium and 7. I definatey don't wear the same size as a 5-year-old!
If she's big for her age it might, this is a juniors small, would be the same as a womens XS. If you think that would fit her. I can get measurements for you if that would help everyone :)