Kara Zor-El, nicknamed Supergirl by Barry Allen, was the cousin of Kal-El who was sent to Earth after the destruction of Krypton, being captured and tortured in an old base in Siberia until being saved by Barry Allen, his alternate self and Batman.
Where did Supergirl come from if Krypton was destroyed?
Depends on what Universe, but her general history is that she is the cousin of Kal El. In the original comics, a city of krypton survives the planets destruction. However, the residents of the city slowly die of radiation poisoning. Zor El sends his daughter to earth to be raised by her cousin.
Kara-Zor-El is the heroine known as Supergirl. Born on Krypton to Superman's uncle and aunt, Kara was rocketed to Earth by her father to save her life. She was adopted by the Danvers family and became the protector of National City. In her secret identity she is Kara Danvers, a run-of-the-mill high-schooler.
During the Invasion Mon-El and Kara had an affair which led to Kara's pregnancy with Mon-El's child. Mon-El kept the child a secret from his mother. Rose was born on Earth during the invasion of the Daxamites. Her father was "forced" to marry Lena Luthor and his mother said that they will produce an heir.
Kara and Trent continue to age into their late teens, and after having sex with each other, Kara gets pregnant at a rapid pace. She gives birth, but the baby dies due to the time rapidly passing. The attempts to leave grow increasingly tense as Charles's worsening schizophrenia causes him to kill Brendan.
In the long history of the DC Universe, one of the most powerful beings to ever exist is, naturally, the daughter of Superman and Supergirl. But since the two heroes are Kryptonian cousins, their superpowered offspring has a forgotten Superman-family replacement to thank for her creation.
She was roughly 25 when she donned Supergirl's colorful costume and she is now about 30 years old when Supergirl season 6 begins. There's a significant discrepancy with her age since Kara is actually much older than 30 - in Krypton years, Kara Zor-El is 54 years old.
Supergirl is killed by General Zod… multiple times.
He never made it here, because Zod intercepted the pod and tried to harvest his blood. “What did you do?” Kara screams. “The infant did not survive,” he says. She gives him a mighty beatdown, but he eventually impales her with his arm spike, just as he did to Jor-El.
Almost all Kryptonians were killed when the planet exploded shortly after the infant Kal-El was sent to Earth. In some continuities, he is the planet's only survivor. In other versions of canon, there is a last daughter of Krypton Kara Zor-El. She is a cousin of Superman and known as Supergirl.
How old was Kara Zor-El when Krypton was destroyed?
When she was thirteen years old, Kara was sent to Earth from the dying planet of Krypton, charged with protecting her baby cousin Kal-El. Her mother told her that due to Earth's yellow sun, she'd have extraordinary powers and go on to do amazing things.
Despite it being the most obvious choice, the Superwoman mantle has quite a dark history unbefitting of a hero like Kara. After she survived Krypton's destruction and eventually made her way to Earth, Kara discovered that her baby cousin was now a full-grown man and the planet's number one protector.
Kara appeared to use that persona like a mask to run away from her past trauma. Doctor Fate diagnosed Supergirl suffered from a severe case of survivor guilt and PTSD, and "Dark Supergirl" was a physical manifestation from her psychological trauma, which was literally crushing her.
It was the custom on Krypton for women to take their fathers's full name for their family name . Supergirl's father was Zor -- El, so she was Kara Zor -- El . Superman's mother was Lara and his maternal grandfather was Lor -- Van, so she was Lara Lor -- Van .
So despite the Silver Age outlier, it's accepted that Supergirl is indeed older than her cousin, at least in terms of who was physically born first. However, no matter how many years Kara can claim, the end result is her being younger than Superman.
Technicalities aside, it's safe to say Supergirl first arrives on Earth as a teenager in both the Silver and Modern ages of comics - 15-16 years old to be exact. The only thing that changes is her relationship to Superman as either his younger or younger-but-technically-older cousin.
In the comic continuity no, Supergirl has never canonically had any biological children. In fact, it was only very recently that her distant relative Kal-El had a son with Lois Lane under the name of Jonathan Kent.
Alura is the Kryptonian daughter of In-Zee, wife of Zor-El, mother of Supergirl, and paternal aunt (by marriage) of Superman. Created by writer Otto Binder and artist Al Plastino, the character first appeared in Action Comics #252 (May 1959).
While Supergirl is clearly replacing Superman in the story, the reason for the change is likely to do with the real-world production of The Flash. At the time that it was being made, Henry Cavill was seeming out of the DCU, meaning the movie would either need to recast the character or replace Superman entirely.
So if Superman and Wonder Woman have a child, and she / he inherits Wonder Woman's strength and Superman's ability to absorb sunlight, that child would have 1000X of strength without sun and in the presence of sunlight it would have 1000000X.
Portrayed by Elizabeth Tulloch, Lois is a reporter for the Daily Planet and the wife of Clark Kent / Superman. Tulloch also played alternate versions of Lois Lane in the Arrowverse television series The Flash, Supergirl, Arrow, Batwoman, and DC's Legends of Tomorrow.
On New 52 DC Multiverse Earth-38, Supergirl is Kara Kent, the daughter of Superman and Lois Lane on an alternate Earth where Superman and Batman began their careers in the 1930s, married in the 1940s and had children in the 1950s.
