Final answer:
Dr. Selina Sigafoose-Jackson was the first woman to earn a diplomate from the DACBR, a designation of advanced expertise in chiropractic radiology.
Step-by-step explanation:
The first woman to earn a diplomate from the Diplomate of the American Chiropractic Board of Radiology (DACBR) is Dr. Selina Sigafoose-Jackson. The DACBR is a designation indicating that a chiropractor has specialized expertise in radiology, and Selina earned this qualification by meeting stringent education and testing requirements. However, the individuals mentioned in reference information provided, such as Margaret Floy Washburn and Inez Beverly Prosser, are noteworthy women in the field of psychology.