Rather than rehash all the excellent work Michael Pinto at Fanboy.com has done chronicling her amazing life, we’re just going to point you to his article:

At the end of the silver age of comic books (which was sometime the early 70s) there was a well known cigarette ad campaign which would proudly proclaim to the ladies “You’ve come a long way, baby.”
But sadly while the wider world of publishing started to open up to
women, the comic book biz was — and still today largely a boys club.
Now I can already hear the indignation from my fellow fanboys, but
here’s the evidence:

Tomorrow is the 80th birthday of a living legend in the field of comics — yet sadly in my humble opinion not enough people today know the name Marie Severin.
Yet like a Stan Lee or a Jack Kirby by all rights Severin should be one
of a handful of names that every fanboy (and fangurl too) knows.