Jane Foster

Jane Foster is the deuteragonist in Thor and its sequel Thor: The Dark World. She is a brilliant astronomer and cosmologist, and also Thor's partner and love interest. She is portrayed by Natalie Portman.

Jane Foster was created by Stan Lee, Jack Kirby, and Larry Lieber.

Personality
Jane is a strong a determined woman, with an obstinate will and an independent spirit. She firmly believes that scientists have been invested with the mission of searching the truth and loyally follows this idealism. She possesses a deep knowledge for her study field, astrophysics, and of her peers, she single-handedly came the closest to discovering the existence of Asgard by studying the wormhole-like traces left by the use of the Bifrost Bridge.

She is also slightly quirky, and can have a feisty attitude if provoked.

The Avengers
Although she didn't appear in The Avengers herself, her picture was shown in a monitor when it was mentioned by Coulson to Thor that she is taken to safety; he states that she was sent to work at a museum in Tromsø, Norway, all expenses apparently paid.

Thor: The Dark World
"We're from different worlds, maybe they were separate for a reason."

- Jane Foster

Jane Foster is an astrophysicist who met Thor when he was exiled to Earth by his father. The two had an intense attraction in the short time they were together, and through Jane, Thor learned the value of humility and the heroic nature of humanity. After being separated since Thor’s first visit to Earth, Jane has moved on with her life… but now finds herself pulled into Thor’s world once again by an ancient evil.

While Jane was on a date, Darcy appears to inform her that was a gravitational anomaly. Despite not wanting to leave her date, Jane accompanies Darcy. During the investigation, Jane is on his own and is lost for four hours, also the Aether entered in her body. When Jane scolds Darcy for calling the police, Thor appears. Jane goes to him and slaps to verify that it was he, suddenly a policeman approached them wanting to arrest Jane, Aether defends Jane. Seeing this, Thor decides to take Jane to Asgard to cure her.

When Odin sees that the strange energy protect Jane, the All-Father tells the story of the dark elves and Aether. Jane ask Odin if there was a way out of her body but he says he does not know. During the attack of the Dark Elves, Malekith asks Jane to give him the Aether but seeing it was an illusion made by Frigga, Algrim kills the Queen of Asgard, after the attack Odin puts into custody Jane.

Thor decides to make a plan to save Asgard and Jane from Malekith, the plan was to freed Loki from his confinement, meanwhile Sif freed Jane from the Einherjar. In Svartalfheim, Malekith removes the aether from Jane's body, Thor tries to destroy the gem but he failed in his attempt. In Greenwich, Jane with the help of Dr. Selvig and Darcy placed devices to try to control the anomalies.

When Thor defeat Malekith, Jane runs to help him as a Dark Elves' ship fell on him, however both are saved by Selvig, while in the dark world the ship that Selvig teleported Selvig fell on Malekith, killing the dark elf. Jane was shown sad when Thor went to Asgard, her Darcy tried to cheer her saying that he was going back. In a post-credits scene, Thor returns to Earth and shares a kiss with Jane.

The Avengers: Earth's Mightiest Heroes
In "Thor The Mighty", Jane go with her partner where the Wrecking Crew are attacking, during the attack by supervillains, Jane shows her bravery that draws the attention of Thor. The talk between Jane and Thor was interrupted by Heimdall. When Thor decided to go to Earth, Odin mentioned Jane as a reference that humans can defend themselves.

In "Breakout, Part I", while Jane heal a patient, a car crashes and goes straight to her but Thor prevented this saving her life. Jane asked Thor if he was following, Thor says yes because he was intrigued in humans. Thor and Jane have a date, the Asgardian tells Jane that his father sleeps a week to renew their powers. Then Jane asks him to go to Asgard, suddenly the Breakout starts.

In "Michael Korvac", Jane makes some tests to Korvac at the request of Wasp.

In "Behold...The Vision", she and Jan were watching a horror movie at the mansion. Suddenly, Vision appears demanding to know the location of Captain America's shield. Seeing as Vision was hurting Wasp, Jane tells the location of the shield, Vision then retires to address Wakanda. Later, Jan told Jane to reconsider not date with superheroes for her safety.

Avengers Assemble
Jane appears in the show's fourth season. Initially she was assisting the Avengers in building a machine to bring Iron Man back from another dimension. However, when the rest of the original Avengers also get zapped into different dimensions, she is also tasked with finding them while other heroes serve as the Avengers of Earth. Eventually, the original Avengers have return, and she would aid both teams to stop Loki from causing Ragnarok on Earth. At sometimes later, Jane ended up on Battleworld and became the sheriff of the Westland region. During the battle against the Beyonder, Jane is caught and began to sink in his quicksand trap. In a last moment effort, Thor throws Mjolnir to her, and she was deemed to be worthy, thus received the power and becoming a new, female Thor. After the battle with Loki, Odin bestow her an enchanted Asgardian mace and granted her the name Thunderstrike.

Trivia

 * In the comics, Jane Foster starts as a nurse, instead of an astrophysicist; the studios wanted to update the character. She is enamored with Donald Blake having broken up with Thor decades ago in the comics.
 * In the post credits scene of Thor: The Dark World, Jane is portrayed by Elsa Pataky, Chris Hemsworth's wife, in using CGI technology.
 * In the current comics, Jane is currently a female version of Thor and the wielder of Mjolnir, being one of the few people deemed worthy, but is suffering cancer. Thor himself had become unworthy of Mjolnir towards the end of the Original Sin event and now, going only by "Odinson", he wields the battleaxe Jarnbjorn.