50 and 5'2" here, a curvy size 12 on a good day or 14 on a fat day.
Some good brands that may not have been mentioned (thanks for all the recommendations):
~ NYDJ do petite, the leg is about 29inch but shrinks to about 28
~ J Crew petite is OK for work, as is Banana Republic
~ Joules jackets are short in the back, so only the sleeves need taking up
~ Ralph Lauren wrap dresses "normal size" are short in the back so fit we shorties.
~ Monsoon dresses usually fit. Many of them have straps you can slide to tighten, or they lift easily.
~ Lands End do good basics, such as T-Shirts, shorts and chinos