Within her cousin's shadow, Kara Zor-El forges her own path.
When a character becomes successful, their supporting cast often shares the benefits. At the same time, however, that supporting cast becomes anchored to the shadow of another character. Most of the time, it's impossible to escape that shadow. Dick Grayson can create a new superhero persona in Nightwing, thrive in his own series, and hook up with an alien princess all he wants. He'll still always be tied to Batman. He'll still always be a supporting character whose success isn't entirely his own.
Supergirl faces a similar situation, albeit in a different set of circumstances. It's not just because she has a successful TV show and Dick Grayson does not. In many ways, Supergirl faces more daunting challenges in establishing her own narrative. Her story is inherently tied to that of Superman, one of the most iconic heroes of all time. To say he casts a large shadow is like saying Gotham City has a minor PR problem. With the recent death of the New 52 version of Superman, and his subsequent replacement with one who is just like him, Kara Zor-El doesn't even get a chance to step up.
That doesn't mean that she can't forge her own story. She just has to craft it with the knowledge that DC Comics will never let Superman's shadow shrink by much. This, along with the profile of having a hit TV show, gives Steve Orlando and Brian Ching plenty to work with in Supergirl #1. They end up making the most of it and they do it without casting Calista Flockhart.
While Supergirl may live in the shadow of her famously iconic cousin, her story has some important differences that does a lot to set her apart. Unlike Superman, she comes to Earth as a teenager. This means she has vivid memories of her life on Krypton. She remembers her family, her friends, and any annoying neighbors she may have had over the years. Most of her life is on Krypton and that life literally blew up in her face.
It makes Kara Zor-El's journey more compelling because her situation makes her more alien than her cousin in the sense that Earth is so new to her. Superman, having arrived on Earth as an infant, sees this world as his home. It's the only world he truly knows. Supergirl still sees Krypton as her home and Supergirl #1 explores the difficulties this creates. Add being a teenage girl on top of this and these difficulties are almost on par with kryptonite -- they can weaken her.
Orlando makes a concerted effort to focus on these distinctions early in the story. We get brief glimpses of Kara's life on Krypton compared to her life on Earth. Unlike her cousin, she has a life on her home world. She has hopes, dreams, and aspirations, like any wide-eyed teenage girl. By Earth standards, it's not what we would call a typical. It's abundantly clear that Krypton does things differently and not just because their schools don't play dodge ball.
Since this is a planet that eventually blew up, it's easy to forget that it still harbored an advanced alien race. Their technology, even for junior high school kids, makes Earth's smartphones look like glorified bricks. It means Kara, despite being from an advanced race, is going to struggle when she tries to live the life of a normal Earth girl.
That life still involves being Supergirl. Orlando takes full advantage of the dynamics surrounding DC: Rebirth to resolve the outstanding issues with Supergirl's story from the New 52. This means she can get back to basics, picking up on crimes with her super senses and fighting them off in a way that seems much easier than a typical day of high school. There isn't much complexity to this part of the story, but given the scope and context of this story, there doesn't need to be.
Within that same scope and context, there's another key distinction. Whereas Superman does what he does by himself or as a leader in the Justice League, he doesn't answer to anyone. Supergirl does have some additional bureaucratic oversight in the form of the Department of Extra-Normal Operations. She also has foster parents who will oversee her with parental scolding. Both have plenty of potential to complicate her activities as Supergirl in ways her cousin never had to deal with.
While it seems like a burden, the logic behind this oversight does make sense, at least in the way Director Chase describes it. She rightly points out that her cousin spent his whole life on this planet, learning how to use his powers and live within Earth's human culture. Kara has barely been on Earth long enough to binge-watch old sitcoms on Netflix. She shares her cousin's innate desire to help others, but lacks his refined skills. Even rebellious teenagers can't ignore that kind of logic.
This creates an underlying mood of frustration and uncertainty with Kara. She doesn't get overly angst-ridden, which tends to happen with too many teenage charters. However, there are times when her emotional responses feel flat. It's Supergirl #1's primary weakness. Orlando does a lot to establish her new journey and explore who Kara Zor-El is as a person. Little is done to explore her personal sentiments, which limits the overall weight of the story.
Little detail is given of her supporting cast, as well. Her foster parents come off as caring. Even the hard-nosed bureaucrats at the DEO seem reasonable. However, not much is done to give this supporting cast any real depth. Only Cat Grant shows a significant amount of personality in this issue. Then again, that's to be expected of Cat Grant. Our expectations for the rest of Supergirl's supporting characters leaves much to be desired.
This doesn't take away from the major accomplishments of this story, however. The biggest challenge of any character bearing the emblem of Superman is crafting a story that isn't solely defined by Superman. Like Dick Grayson, Kara Zor-El may never be able to escape her cousin's shadow, but Supergirl #1 shows that she can still follow her own unique journey.