Timely's Catwoman is a foe of The Angel, one of the publisher's longest running and most popular heroes. In Marvel Mystery Comics #63 (April 1945), "A new ferocious creature makes her debut in crime/ endowed with amazing strength, incredible agility, and ruthless cunning, she pits her wits against The Angel in ... The Horror of the Catwoman!"
Since she's a villain, we get no back story. And since this is the Golden Age, she pays the ultimate price for her criminal activity.
The following pages were scanned from fiche and aren't the highest quality, but they'll have to do for now.