The character's name, appearance, and personality were patterned after Johns' 18-year-old sister Courtney, who died in the explosion of TWA Flight 800 in 1996.

[3] Courtney Whitmore, stepdaughter of Pat Dugan, finds the original Star-Spangled Kid's gear in her stepfather's belongings.

She dons the costume to annoy Dugan, as she resents him marrying her mother and moving the family from Los Angeles to Blue Valley, Nebraska.

[4] During her time in Blue Valley, her frequent nemesis is the young villainess known as Shiv, daughter of the immortal Dragon King.

Driven further into madness by the Joker's chemical assault, Grundy attacks the JSA headquarters with the head of the Statue of Liberty.

[10] Later, she discovers her biological father Sam Kurtis working as a common thug for an incarnation of the Royal Flush Gang.

A glimpse into the future shows an adult "Starwoman" married to Albert Rothstein, the JSA member known as Atom Smasher.

Knight had become clinically depressed for his perceived role in the creation of the atomic bomb to the point that he initially thought Courtney was a hallucination, but she was saved by a figure later identified as Starwoman, an adult version of her infant sister Patricia.

After the crisis is over, Courtney forgives Al for his past alliance with Black Adam but Atom Smasher is nearly killed by the Spectre during an attack on Khandaq.

Stargirl becomes part of a coalition consisting of the JSA, the Doom Patrol and the Teen Titans that is organized to stop Superboy-Prime from destroying Smallville.

[17] A seasoned hero despite her age, she forges a bond with her young teammate Cyclone, the eager and over-impulsive granddaughter of the first Red Tornado.

They two bond after witnessing the death of Mister America and Courtney suggests Cyclone create a new superhero costume and name.

[18] Stargirl resumes her role of mentorship for the youngest heroes by helping Jefferson Pierce's daughter, Jennifer, cope with her powers and her isolation.

[22] After the battle with Black Adam and Isis, Courtney was unhappy, as the events had happened on her birthday (and had ruined any planned celebrations).

When she goes home and opens the door, the entire Justice Society is present and have prepared a late surprise party for her.

Though Pat agreed to train her, Courtney had to respond to the criminal activity caused by Shadow Thief who was taking hostages to draw out a superhero.

When Stargirl returned home, she found that Shadow Thief arrived first, killed her brother, and wounded Barbara and Ted.

When wearing the Cosmic Converter Belt, Stargirl has enhanced strength, speed, agility, and stamina as well as the ability to project shooting stars.

[citation needed] Courtney Whitmore as Stargirl was originally going to appear in Black Adam as a member of the Justice Society of America, but was cut from the film.