I am in need of the distribution of women's shoe sizes in the US. 
Preferably ages 25 - 50.

Hello Susanfish,


Ladies footwear size figures

The following chart gives the breakdown of the percentage of shoes
sold for each half size of ladies shoes in the U.S.

Women?s Size     Percent sold        
4                0.9%
4 ½              0.2%
5                1.8%
5½               1.9%
6                5.9%
6½               5.8%
7               12.5% 
7½              11.2%
8                 16%
8½              11.8%
9                 13%
9½               4.5%
10               9.3%
10½              0.7%
11                 3%
11½              0.1%
12               0.8%
12½              0.1%
13               0.3%
14*             <0.1%
Courtesy of  Footwear Market Insights

Source: 
Footwear Impression Evidence: Detection, Recovery and Examination,
Second Edition by   William J. Bodziak


Amazon: Page 191
Use the ?Search inside? feature with keywords Ladies shoe sizing
http://www.amazon.com/o/ASIN/0849310458/


Google Print also offers a copy of this chart:
http://tinyurl.com/ymwele




Search terms:
Ladies OR women?s shoe OR shoes percent  sizes 6 7 8 9 
Ladies OR women?s shoe sizing


I hope the information provided is helpful!

Best regards,
Bobbie7

Great work bobbie7!! Thanks