I checked through all the likely cardigan spots in the store, including the plus sizes, the blazer rack, the pullovers (sometimes one kind of sweater gets hung with another), even the women's suits, because you never know. I passed up any sweaters that were very lightweight or very embellished. This was the winner, and actually the only one that fit what I was looking for:
I liked the stripes; they lighten up the dark grey a bit. The sweater goes well with my grey corduroy skirt, and with my pants. It's warm enough, but not so heavy I'm bending under the weight (like one I bought last year). So Yay, to quote Vanita Bentley.
Here's the trick I promised: the large amount of fabric in a shawl-collared cardigan can easily swamp petite people. The easiest fix is to fold the collar and the front edges under. You're not trying to hide buttons or fancy collar details, so it still looks fine, just a bit more streamlined.
As always, thank you to the nice people who donate such good stuff to the MCC store. (Maybe somebody else out there will be blogging about their new grey blazer.)