Shiera Saunders / Hawkgirl

Earth-One / Post-Crisis / New Earth
Shiera was next reincarnated in a very strange way. Her brother Speed’s troubled teenage granddaughter Kendra committed suicide, and Kendra’s spirit then entered her body. She only remembered Kendra’s life, and believed herself to be Kendra, having surivived her suicide attempt. Speed, knowing this was his sister, not his granddaughter, trained her to become the “next” Hawkgirl. After joining the new JSA, Kendra learne the truth. Soon after, Carter was resurrected, not reincarnated, as a grown man with full memories of his past lives.
 * 1)  Carter Hall / Hawkman  - In ancient Egypt, Prince Khufu and his bride Shiera were murdered by the sorcerer Hath-Set. But Khuf swore ebfoer they died that he and Shiera would be reincarnated. And so they were. In the Post-Crisis version, in fact, they were reincarnated many times over the centuries, in each lifetime finding each other and falling in love. In the 1940s, they were reincarnated as Carter Hall and Shiera Sanders, who, after realizing their origin, took the pair of wings made of Nth metal (an anicent metal from Khufu’s period of Ancient Egypt that could defy gravity) to become the superheroes Hawkman and Hawkgirl. They were eventually married and had a son, Hector Hall, who also became a superhero. In Post-Crisis continuity, the two continued their superhero careers into the silver age, before being killed in the Zero Hour event.

Shiera still largely thought of herself as Kendra, and would continue to call herself that. She did not remember her past lives like Carter, and, although attracted to him, was not ready to begin a relationship. Carter understood this.

Although partners, the two were still not together in about 2007, when…

2.  Roy Harper / Red Arrow  and Hawkgirl began to have something of a romantic attachment, sleeping together at least once, while Hawkman had a similar attraction to Power Girl.

DC Animated Universe
In the DCAU, Shiera is shown to be the same character as Shayera Hol / Hawkgirl. Shayera was sent to Earth on a reconnaisance mission, although she told others, even her eventual Justice League teammates, that she was lost from her homeworld. While Justice League teammates, she and John came to love one another.
 * 1)  Katar Hol / Carter Hall  -  Katar Hol and Chay-Ara were Thanagarian travelers and lovers who crash-landed in Egypt and became the king and queen, building the civilzation up into what it was.
 * 2)  Bishari / John Stewart / Green Lantern  - John's former incarnation was named Bishari, Katar's closest friend. However, they carried on an affair, and were eventually poisoned by Katar's assistant Hath-Set.,
 * 3)  Hro Talak  - In the persent life, Shayera was engaged to this fellow Thanagarian military officer.
 * 4)  John Stewart / Green Lantern  -

Eventually, John brought the matter up. Shayera was reluctant to start a relationship, the reason clearly that she was already engaged, but gave in. Shortly later, soldiers from Thanagar came to Earth, and she confessed her relationship to John. Hro himself was also not pleased to hear he had been cheated on.

The Thanagarians then began an invasion of Earth, one which she did not know was being planned. Shayera then turned against the Thanagarians (not soon enough for some to trust her), and Hro left her on the planet after the invasion was defeated. She then resigned from the Justice League in disgrace, telling John she loved him before she flew off. As she faded into the distance, john admitted “I love you, too.” After Shayera rejoined the Justice League, the tension between her and John became palpable, especially since he was now dating teammate Vixen. Despite this, Vixen and her became friends.

John met his and Shayera's son from a possible future, Rex Stewart, who had become a superhero.

3.  Cater Hall / Hawkman  - Carter, an archaeologist, approached Shayera to show her a Thangarian sword from Ancient Egypt, showing that Thanagarians had been on Earth thousands of years ago. He then invited Shayera to dinner to discuss it more. Batman did research on Hall, and found that he had stalked Shayera, showing up at multiple fights of hers with villains. Nonetheless, Shayera went out with him. It was even suggested they spent the night together before, the next day, going to the dig site in Egypt, a tomb, where the sword came from. There Carter revealed that he had experienced visions of their previous life, and believed them destined to be together. Shayera doubted that the reincarnation aspect, but remained interested in Carter.

Later, the so-called Shadowman, actually a personifcation of Carter's mind, free from moral inhibitions, kidnapped Shayera, Cater, and John, and forced them to relive the memories of their previous life, including Chay-Ara and Bishari's affair, which Carter had not previously seen. After seeing this, Carter decided that they were not truly meant to be together, but rather, she with John.

John then revealed to Shayera that he had met their son in the future. However, not willing to be "destiny's puppet," John decided to stay with Vixen (for now).

Smallville

 * 1)  Carter Hall / Hawkman  - Shiera is a part of Carter’s backstory and only seen briefly as a hallucination. She and Carter became Hawkman and Hawkgirl and became found members of the JSA in the 1970s, before she died.  Carter later is killed in action, paving the way for the reincarnation of both.

Arrowverse
Later, the team encounters a future incarnation of Carter. Helping him to regain his memories, Kendra begins to feel more for him. She ends her engagement with Ray and decides to leave the team to have adventures with Carter, although romance is still not yet present.
 * 1)  Carter Hall / Hawkman  - In a loyal but simplified version of the story, Carter maintains his full memoreis of his past lives, while Kendra, whcih is simply the name of this incarnation of Shiera, does not. They become superheroic partners, but not lovers. The two join the time-travelling superhero team the Legends, but Carter is killed shortly after.
 * 2) Ray Palmer / The Atom, Kendra’s Legends teammate, then enters into a realtionship with her. On one mission, they are stranded in the 1950s and live together for two years. After they are rescued by the team, Ray proposes. Kendra meets a 19th century incarnation of herself who warns that any time she tries to have a romance with someone other than Carter, it ends in tragedy. She still decides to accept Ray’s proposal.