I am 5 foot 1 inch, and about a size 10 (12 on a bad day - there seem to be more and more of those though). I have quite a small frame, so standard sizes are nearly awlays too long in the sleeve, body and leg, too wide on the shoulders, assume that the distance between your waist and crotch is much longer than it is etc etc.
Where can I buy clothes that don't look like they belong on a woman in her mid fifties?! I found a fantastic website called Petite Affair, but that's it. I would prefer not to buy mail order, but I would do, if the clothes were good and didn't completely swamp me in the arms, shoulders etc.