There are lots of Spider-people in Marvel Comics nowadays but only one of them has the distinction of being the parallel universe version of Peter Parker's long-dead girlfriend. Making an alt-Gwen into a superhero is a good twist but it's not the sole reason that readers should check out her adventures.
Gwen Stacy actually fights crime as Spider-Woman in her native reality, which we first saw in the Edge of Spider-Verse miniseries a while back. But the Spider-Gwen nomenclature works because it immediately encapsulates the appeal of having Spidey's dead girlfriend get re-invented as an analogue of Marvel's famous wall-crawler. These are the best parts of Spider-Gwen — executed by the creative team of Jason Latour, Robbi Rodriguez and Rico Renzi — so far.
Gwen's Got Great, Complicated Parental Drama
Gwen's relationship with her dad simultaneously upends and pays homage to the old-school secret identity struggles that Peter Parker used to deal with in the mainline Marvel Universe. Peter used to worry about how the revelation of his double life would impact Aunt May's frail health. In Gwen's life, the tension comes from having a dad who's a police captain. She's already revealed her superhero life to him but, if their connection becomes public knowledge, the revelation could kill Captain Stacy's career as a cop.
She's an Outlaw But Not an Outsider
Gwen Stacy isn't a shy, misunderstood introvert like the mainline Marvel Universe Peter Parker. She's a drummer in The Mary Janes, a rock band that feels just one big break away from the big time. Gwen doesn't feel unduly tortured or put-up on. Sure, she's wanted by the police and has the stress of a superhero double life but Gwen feels like a relatively normal teenager at her core. Not true for her high-school friend, though...
Sure Seems Like Her Version of Peter Parker Was Disturbing
The great "power-&-responsibility" tragedy that motivates Spider-Gwen is the death of her universe's Peter Parker. His demise was brought on by experiments that changed him into that reality's version of the Lizard, which he did after getting bullied.
But in issue #4 of the previous volume of Spider-Gwen, Aunt May told Gwen that Peter was losing touch with reality in an uncomfortable way.
This beat is a great subversion of the mainline Peter and also locks in readers' sympathies to Gwen. Even if this reality's Peter Parker comes back to life, he probably won't be a guy who's easy to cheer for.
The Alternate Takes on Familiar Characters Are Pretty Great
Spider-Gwen is essentially an extended What If, where that fateful irradiated spider-bite happens to someone else. And like all great re-jiggered superhero mythos, it's got plenty of re-invented familiar faces for longtime fans to encounter. Frank Castle isn't a kill-crazy psycho-vigilante here; instead, he's a rule-breaking cop with a taste for rough justice. And Daredevil doesn't exist. A very creepy Matt Murdock works for the Kingpin as his right-hand assassin/lawyer.
New riffs on established characters seem to be showing up on a pretty regular basis, giving us a sense of just how different this dimensional plane is from the one we know.
Spider-Gwen Works Great Without Being an Exact Replica of Old Spider-Man Storylines
If you stripped away all of the references to the decades of Spider-lore, the character tensions and subplots in Spider-Gwen would hold up well on their own. The garage band aspirations, daddy's-girl-all-grown-up dysfunction, crime-fighting work-life balance issues... all of it works without being derivative of Peter Parker's long, well-loved publishing history. Spider-Gwen owes some of its recipe to the Spider-stories of the past, to be sure, but it's enough of its own thing to feel modern and unique.