This is fun!
Anne and I have long joked that we are near body doubles! There are slight differences, though. For example, Anne, by doing Imogen's proportion exercise I recently learned (to my shock) that I am SHORT-waisted!! Duh, so that's why petite jackets fit me best!
I'm 5'4". Shoulders measure 39", bust is tiny (32"), waist 25", hips 33.5."
Despite the absence of curves up top, muscular legs and bootie make me a cross between a rectangle and a slim hourglass.
Proportionately: Large head, long neck, short waist, also a little bit short from waist to rise (again, to my astonishment!). Short(ish) legs, but somehow or other my top half and bottom half come out proportionately equal.
Sizes vary, depending entirely on make and brand. Usually a 2 in denim, anywhere from a 2 petite to a 6 petite or a UK 8 in jackets (where I need room for my shoulders); 2 or 4 petite in blouses, 0 or 2 petite in bottoms, although I can't wear most petite pants because the rise won't fit and they won't be PPL. But jackets, skirts, and dresses usually work better than regular sizes. Best of all are European sizes; the jackets and shirts tend to fit me best with no need to shorten the sleeves - yahoo!! Often a French 36 is right; not sure of the Italian size. However, I don't put much reliance on what it says on the tag. I just eyeball stuff and take it into the dressing room!
Shoes: European 37, somewhere between 6.5 and 7.5 US sizing.
Joy, I think you and I may be near twins, except for my bootie and your sweet tum and longer limbs.
I pay attention to how clothes look on all the shorter women who wear petite sizes, even if their body types differ. It gives me good information, especially if I am planning to buy something in the same brand.