Non-Canon Fanmade Crack Ship
Jelsa was created by fans in 2013 believing that Elsa from Disney's Frozen and Jack Frost from DreamWorks' Rise of the Guardians was a good pairing because of their winter powers.
Jack Frost's and Elsa's movies' do not correlate with each other, though, Jelsa fans do so by making the characters OOC a.k.a. changing their personalities and the movies' storylines in order for the two main characters to meet. Two examples: 1. They take Anna out of the picture, who was the one to help Elsa with her problems, and replace her with Jack instead (they remove the sisterly bond the Frozen movie was centered around). 2. They remove the scene in ROTG where Jack tell's MiM (Man in the Moon) that he's tried everything and no one ever sees him.
There is no other similarities between Elsa and Jack Frost to what the fans believe. Neither of them sacrificed themselves for their sisters; Jack was propelled toward the crack in the pond's ice his sister Mary stood on as he used his crook to save her. Elsa's parents kept her hidden away to protect the village from her uncontrolled powers. Jack Frost is the embodiment of winter whilst Elsa was born with her powers due to her mother saving their father as told in Frozen 2.
The creators of Frozen did not make Elsa immortal, and as well, claimed that they will never give Elsa a love interest.
There is nothing more about Jelsa that is at all interesting even of the fact that fans take clips from the movies and create YouTube video edits and screenshot edits. (Annoying and ridiculous!)
DreamWorks (owned by Universal Studios) and Disney are rival companies that will never combine their movies to create crossovers.
Link:
https://twitter.com/heybilljoyce/status/1263772536061538305
Yes I despise Jelsa with a passion, as you can see in the tags.