Thanks to other reviews, I knew before buying that these were sized more like juniors, than women.  If it helps you...
This was purchased for a 53 105lb Fit female.
A womens MEDIUM fits tightly, just reaches the hips, a bit too narrow for the shoulders, but the shirt stretches, so its easily wearable.
A womens LARGE fits tightly, reaches the hips, fits the shoulders.
A womens Xlarge hugs, but not too tightly, reaches just below the hips, fits the shoulders.  Probably the best fit for someone this size/shape.
The MENS shirts of this brand are the same quality, but the mens medium fits this same frame in the shoulders, hangs loosely (but not too baggy), and falls blow the hips.  (Fits more like a fitted mens small)

Outside of the measurements, these are actually super comfortable for both working out/running and lounging about.  The material is really soft.  But Im also guessing you get what you pay for.  No idea of the durability, but well see.  Shipped quickly.