DH is being Dined Out of the army reserve on Saturday. I have just discovered that I have to wear a long dress, and my shoulders have to be covered. Minimal budget, can get to major stores but not John Lewis, 5' 3", 10-12 with wobbly tummy, happy to invest in spanx but am 56 and it's the army so not something clingy.
If you have a suitable length dress already, it's normally allowed to cover your shoulders with a pashmina or scarf. The easiest way tens to be to drape it over your shoulders then tie the ends behind your back, after they've gone under your arms. Then it's not flopping around in your food!
I am 5'2" and have seen lots of evening dresses in Debenhams this week. Our one has Wallis Petite, Principles Petite, Précis Petite, plus there are loads of shrugs and cardigans there at the moment. (I was shopping for a knee-length dress for formal dinner).