FYI, I tried on the mollie jacket, carrie hoodie and bella vest in a store recently. If I were buying them, I would probably go with Mediums to layer over my Small shak, although the store I was at didn't have them in smalls to compare. The Mollie Jacket is very heavy, its a real wool coat, much heavier than the carrie hoodie. I am a 4-6 on the bottom and 6-8 on top (depending on brand). I am a solid small on top on all other pieces I tried in ibex (shak, kate, ribbie), icebreaker, and llbean, but when I want a piece to layer over something heavy I buy medium (like my PI gavia jacket, PI vagabound II jacket, and craft rain jacket).