February 15, 1943 "LIFE" magazine (on the cover, the about-to-be-queen, Princess Elizabeth.) In the pages of this issue, we read: The pin-up girl is one of the distinctive social phenomenon of our time.
 
The American male has so long accepted the cinema star as the ultimate in desirable womanhood that he has developed a curiously personal attitude toward her. He has no more hesitation about asking for her picture than he would in asking his best girl. For often these days, in bleak barracks and distant lands, the pin-up girl is the only girl he has.  Anne Gwynne was one of the top five pin-ups of World War II, as stated in the  February 15, 1943 "LIFE" magazine article on Pin-up Girls of WW II.

HOLLYWOOD, from 1939 on -- ONE OF THE MOST BEAUTIFUL AND PHOTOGENIC actresses in Hollywood, Anne Gwynne started her career as a swimsuit model. After Universal Pictures signed Ms. Gwynne to an exclusive contract at the age of 20, the Studio photographed scores and scores of swimsuit shots of actress Anne Gwynne.

The pin-up girls were rated by the amount of mail received from GIs requesting autographed pin-up photographs.  The Top Five in 1943 (in no particular order) were Dorothy Lamour, Ann Sheridan, Maureen O'Hara, Anne Gwynne and Alexis Smith.  [Ironically, Betty Grable was missing from the list, as number six's slot was taken by then newcomer Janis Carter. Ms. Grable must have made her splash in 1945]

Anne Gwynne was also one of the most photographed women during World War II.  Ms Gwynne was selected a YANK MAGAZINE Pin-up girl five times. 

February 15, 1943 "LIFE" magazine