One dress that I really liked is this chiffon, satin and lace one-shoulder dress with a ruffle flower on it. I like the one shoulder neckline-- I personally don't think I look great in strapless dresses. I love the lace look. It goes along with her theme of burlap and rustic. 
[http://www.dressfirst.com/A-Line-Princess-One-Shoulder-Sweep-Train-Chiffon-Prom-Dress-With-Ruffle-Beading-018004848-g4848][chiffon prom dresses from dressfirst]