TODAY IN COMIC BOOK HISTORY: Dec. 3, 1942
In the pages of Captain Marvel Adventures #18 we learn Billy Batson has a long lost twin sister, Mary Batson. Mary is based off of actress Judy Garland by artist Marc Swayze and soon gains the same powers as her brother and is later dubbed Mary Marvel.
Mary Marvel would go on to headline her own book with supporting characters such as Uncle Marvel. Although Wonder Woman debuted a year earlier, Mary Marvel gained a great following especially from younger girls.
In the mid-fifties Fawcett Publications ceased the Mary Marvel books and all the Captain Marvel Family titles due to a copyright lawsuit by DC, and they wouldn’t be seen again for 20 years.
Mary Marvel has all the powers of her brother derived from Greek Gods. These include speed, strength, stamina, wisdom, power and courage. Saying the word "SHAZAM!" will transform her from Mary Marvel back to Mary Batson and vice versa.