I finally found something I own in a petite small. Unfortunately it's kind of basic but I thought I would ask anyway because I can't keep it. It's just a plain white buttondown, 3/4 sleeves, from BR. It's too short for me and too high maintenance (I don't iron on principle). Let me know if you would like it. I can take pictures but it's really a pretty generic white shirt (nice quality and shape though).