Sizing is wacky all over the place. I'm a petite-to-average-framed 5'5", and normally run between a small and medium in ladies' sizes, or large in "juniors" at department stores. I recently ordered a casual sleeveless top from TE that the item page warned ran big. So, I got the size small (the smallest available) figuring it would be fine, and was absolutely swimming in it. I had to return it.
'09 Jamis Satellite Femme | stock Jamis Road Sport -- road
'08 Trek 7.2FX | Terry Cite -- commuter
'77 Raleigh Grand Prix mixte | stock Brooks (vinyl) -- just for fun!