- Supergirl is Superman's cousin from the planet of Krypton.
- Kal-El was sent to Earth as an infant, but Kara faced a lot of trauma since she witnessed Krypton fall apart and all her loved ones die.
- While Superman holds back and is a beacon of hope, Supergirl does not hold back as much and is a much fiercer combatant.
Kryptonians have been a massive part of the DC lore since the very dawn of the universe. As a matter of fact, Superman, a Kryptonian, was the first superhero to be introduced by the comic book company back in 1938 during the Great Depression. Now, while Superman gets his fair share of attention, other Kryptonians often live under the shadow of his cape, such as Kara Zor-El, or Supergirl. Now, after quite some time, James Gunn has decided to bring Supergirl to the forefront in the DCU with Supergirl (2026), so it’s only fair that we learn more about Supergirl in DC Comics as well as how she is related to Superman.
What Is the Origin of Supergirl aka Kara Zor-El?

Superman, as a hero, has become a synonym of hope and a compilation of everything good in the world. However, when we talk about Supergirl, even though born with the same ideals, she was forged with a different kind of metal. Introduced in Action Comics #252, released in May 1959, Supergirl was introduced as Superman’s long-lost cousin. When Krypton was being destroyed, and Kal-El was sent to Earth, a teenage Kara was launched into space at almost the same time to act as a guardian to the infant on their new home.
However, her ship was struck by the shockwave arising from Krypton’s destruction, pushing it into the Phantom Zone. While Kal-El grew up with loving parents and became Earth’s saviour, Kara was trapped within the Phantom Zone in a stasis for 24 years. Then, her ship’s engines were rebooted by Indigo, allowing Kara to escape and crash on Earth, where she was discovered by Superman.
How Is Supergirl Related to Superman?
Canonically, Superman and Supergirl share the same set of powers as they are cousins, but Kara proves to be much stronger than Clark simply because she refuses to hold back as much as Clark does. Another massive difference between the siblings stems from their ideology and past. When Clark left Krypton, he was a mere infant. Growing up, he didn’t even remember Krypton, but on the other hand, Kara was involved in the fight for Krypton. Even though a teenager, she faced combat and was battle-hardened, witnessing her loved ones die in front of her eyes.
This emotional and mental scar molded Kara’s character into a rather fierce combatant who does not believe in holding back as much as Superman does. However, over time, with Superman’s guidance, Supergirl became softer and learned to put her faith in Superman’s values.
With Supergirl coming to DCU next year, the polar opposite dynamic between the siblings would be a treat to witness on the big screen. So, all we have to do is wait and see if James Gunn manages another bullseye in 2026 or not.