Despite the name, and the fact that this character debuted not long after the alternate-universe hero Spider-Gwen, Gwenpool has no relation to Gwen Stacy. Well, she has one small connection, but it’s not story-related: she was born out of a variant cover design that mixed Deadpool with Gwen Stacy. But when she was introduced as an actual character in Marvel Comics, she got her own origins and personality.
Gwen Poole, who debuted in the pages of Howard the Duck, comes from another dimension, where all of the Marvel heroes and villains are fictional comic book characters. When she arrived in Marvel’s primary 616 universe, she came to the conclusion that everything around her was part of that fiction, and subject only to the rules of storytelling. Gwen decided to adopt a superhero outfit of her own and have some wild, psychotic fun.
Consequently, she routinely takes the lives of bad guys and red-shirt bystanders, has no problem letting superheroes know that she’s fully aware of their secret identities, and approaches every conflict with a happy-go-lucky, devil-may-care attitude. She’s quickly become a fan favorite thanks to her bubbly-yet-oblivious personality (which no doubt helped spark the endless comparisons to DC’s Harley Quinn), but when it comes to fighting crime, she usually does more harm than good.