Knitting Machines and Patterns

i need a shrug for my eight grade formal and i want it to be a neutral color (white, black, grey) and i'd prefer cotton or silk and a crochet or a knit if it's a tight, small stitch. i'd prefer a short sleeve and i'd like it to end no farther than my rib-cage. i looked at hollisterco.com, oldnavy.com, forever21.com, wetseal.com, and rue21.com. i haven't been into the stores but if you know of a cover-up like that, please tell me where and if it's an in-store item or not.