A women’s size 6 is not the same as a size 6 label from 20 years ago. In fact, today a women’s size 6 is not even consistent across stores. Since women’s clothing is not standardized to actual measurements, clothing size becomes a starting point only. The lie behind Women’s clothing sizes is further confused by odd number Junior sizing versus Misses even number sizes and inconsistent Plus and Petite options.
Here is a sample of skirts and shorts from my closet. All of these fit right at my natural waist (just above my belly button). All of these are the same measurements at the waist. In every real definitions, each of these are the exact same size. Except when you check the label. Top down; J. Crew skirt is size 8, Boston Proper size 12, WHBM size 6, WHBM size 10, and Ann Taylor Size 8. Even within the same brand, the shorts were totally different sizes! It is time to stop obsessing over the size printed on the label.
Online shopping is a gamble even when ordering a size based on the published sizing guide. At least in store shopping allows for the option to go up or down a size for the best possible fit.
Bottom line, know your measurements and focus on the fit of the garment, not the printed size. Instructions to measure yourself for the best possible fit.