This was a really easy, yet hard costume. Trying to find a blue hoodie in a good color (almost with leggings that matched) proved more difficult that you could imagine. Thankfully I found some online from Old Navy and purchased them quickly. The skirt was purchased at Target.
Using a purple/pink shoelace I added the stitches to the hoodie. It didn't actually have strings for the hood, so I just sewed the end pieces to it to give the effect.
For the leggings I found some red yarn and sewed it lightly on. This picture was taken before we decided we liked it and could sew it on fully and more secure.