Listen little nuts, I live here, I know for a fact that we have plenty of small women. Sometimes I feel big and I weigh a buck 80. 
look at the forarms on many american girls,,,they are as long as forarms on asian guys,,they are longer than other chics forarms,,,the bones are just bigger,,,now when i say 99% its obviously not,,,the % is yet to be determine,,but it is high high high id say at the 80-90%,,
also take a look at american chics face shape!! not too many have oval shape,,tons of square jaw and square face or round,,,tendencey to be either real fat or real musculine if training,,but if they do nothing it is simply tendency to be a chubb chubb
take a look from time to time,,check out their hands,,their finger nails are as flat as yours,,,take a look sometime my friend,,