Elsa's discovery of being the Fifth Spirit in Frozen brings her closer to her parents, as Frozen 2 shows more of their history and how the Northuldra tribes were attacked by Arendelle's soldiers.
The simple version is that her ice powers were a gift from the spirits, bestowed on her because of the actions of her mother, Queen Iduna, in saving her father, King Agnarr, during the battle between the people of Arendelle and Northuldra.
She died and was reborn to take on her true form like has happened in so many stories before. With that transformation, Frozen 2 has made Elsa an immortal spirit now. Like how Frozen 2's other four spirits appear as animals but more than just that, Elsa still appears human but is more than just that.
According to Iduna, Ahtohallan is considered a spirit and is the "mother" of all the other spirits. According to Iduna's notes, Ahtohallan is the source of the magic in the Enchanted Forest as well as those of the spirits, including Elsa's powers.
Then Elsa remembers why she came to Ahtohallan in the first place. She came to Ahtohallan to find out why Arendelle was evacuated and why it was stripped of its natural elements.
Disney Theory: Moana Knew Elsa Was The Fifth Spirit
Why didn't Elsa's mom tell her dad she saved him?
Because of the kingdom's negative feelings towards the Northuldra, Iduna kept her heritage a secret for many years, though she finally told him everything shortly before their deaths. Agnarr and Iduna's oldest daughter (Elsa) was born with the power to control ice and snow.
Elsa discovered that the call was used by Iduna to summon the Wind Spirit to save Agnarr. Elsa also discovered other memories of her mother, from Elsa's own childhood and those that took place before she was born.
It has a slot for November 2024 and November 2025 for “untitled Disney animation”, according to Business Insider. Again, assuming that Frozen 3 is following the same release pattern as its predecessors, it's safe to bet that it will be released November 26, 2025.
In conclusion, Elsa is only the fifth spirit because of her mothers sacrifice of her powers. Queen Iduna was the fifth spirit all along and chooses to save King Agnarr knowing that as a royal, she would need to be with him to have her royal daughters.
The directors have confirmed that Elsa and Anna are both the fifth spirit, as in that their bond is what united the Enchanted Forest and Arendelle, though Elsa is still considered the OFFICIAL fifth spirit.
Three years later, Elsa is 21 years old and set to be crowned queen. The people of Arendelle are joyously preparing for her coronation day. Anna (now 18) is flushed with excitement as the castle gates are opened for the first time since the sisters' childhood.
Based on what Anna and Yelena said, it seems Ahtohallan rewarded Iduna's selfless action by granting Elsa with the power to control ice. So basically Ahtohallan had the intention to create a champion for itself, someone who would bridge the two worlds (maybe to prevent another incident?).
Indeed, as there are no condoms or any other reliable form of birth control in the frontier, there's a real possibility that Ennis really did impregnate Elsa. Sadly, before 1883 could even drop any clues that Elsa was pregnant, Ennis died in the next episode while Elsa died during the finale.
Elsa was also planning to split from the group to stay with Sam, but after many goodbyes, everyone decided they were going to Oregon anyway. Even Elsa decided to leave her boyfriend so she could find out where Oregon was, while planning to return to the plains in June to reunite with him.
Honeymaren, a member of the Northuldra tribe who was trapped in the Enchanted Forest by the curse, could return for Frozen 3 as Elsa's girlfriend based on the two characters' shared chemistry.
There hasn't been any indication that Elsa will have a girlfriend in Frozen III. That said, some fans have theorized that Honeymaren, a member of the Northuldra tribe, will be Elsa's girlfriend in the next Frozen film. Honeymaren was introduced in Frozen II as a resident of the Enchanted Forest.
Anna's parents rush her to the sacred realm, where discussions with the trolls reveal that Elsa was born with her powers/ depigmentation and deafness, rather than them being due to illness or accident. Grand Pabbie troll heals Anna but removes her memories of Elsa's magic.
Elsa was born with blond hair so light that it appears white. Her powers made her hair turn white. If she had not been born with powers she most likely would have had brunette hair like her mother or maybe her dad's light brown hair.
The ice from which the palace is constructed is capable of taking on different colors, such as purple, blue, red and yellow, based on Elsa's emotional state (blue when she is happy or neutral, yellow or amber when she is angry, and red when she is frightened).
The implication, and it's only ever just that, is that Elsa and Anna's mother is herself somehow attuned to the magical forces such that Elsa was given the gift of superpowers. (Why Anna never received such powers is equally vaguely defined: just as Elsa and Anna's father had no powers, so too would she be power-free.
It was after that the decision was made to fully commit to the voice calling to Elsa being that of her mother, Iduna. As Marc Smith, Frozen 2's Director of Story, notes in the documentary, the idea "unifies the movie" since it starts with a flashback featuring Iduna and Agnarr, and it brings those elements together.
Frozen explicitly shows the audience that Iduna and Agnarr's ship has sunk, killing both of the young princesses' parents. It's later revealed in Frozen 2 that the king and queen were traveling to Ahtohallan, a magical glacier in the north, and Frozen's sequel again confirms that Anna and Elsa's parents died at sea.
