Freckles Marvel

Golden Age Origin
Mary Dudely claims to be the niece of  Uncle Dudely, alias Uncle Marvel. Under threat of revealing to the rest of the Marvel Family that he had no powers of any kind, she convinced Dudely to let her tag along with her own Mary Marvel costume. To avoid confusion with the actual Mary Marvel, he named her heroic persona Freckles Marvel, on account of her freckled face.

Mary Dudely had no superpowers of any kind, and was particularly clumsy and prone to hinder those she was helping. However, she was also  an avid fighter  and could knock a grown man down.

Legal Note
Only her apearance in Wow comics #35 is public domain. Her other apearances in Mary Marvel Comics and Wow Comics are NOT, and any of the elements from them, including her city of Marveltown, The vehicle of the Birdmobile, and the names of her immediate family and friends are also not in the public domain.

Marvel Comics owns the trademark for the name Captain Marvel. DC comics owns trademarks for the names Shazam and Billy Batson, and Mary Marvel. In order to use Captain Marvel's name it must be used in the interior of the story, the same way DC does to avoid Marvel's trademark on the name.