Definitely size up!!! I sent my dimensions to the shop and they recommended I get a 3 instead of the 4 I ordered. It was too short and I was so bummed. The dress also arrived stained with what appeared to be grease under the lining and it showed through the tulle. The tulle also had what appeared to be a coffee stain on it and one of the jewels over the arm fell off as soon as I got my daughter dressed for her unicorn photos. I was extremely disappointed with the way the dress arrived in such a poor condition. I also rented the accessory set and the hardband had peach flowers and didn’t match the lavender dress. The flowers were also smashed and one was loose. The cape didn’t match the dress and I couldn’t use any of the accessories I paid extra for. I recommend you skip those. I wanted a floral headband that matched since I wasn’t sure on the color of the dress, but the one they sent wasn’t a match either. I was forced to scramble to find something that matched.