Sif (character)
Lady Sif is a fictional character and superheroine appearing in comic books published by Marvel Comics, and is a supporting character in Thor comics. She is the Vanir Norse goddess of War and Hunt, sister to Heimdall, and friend and love-interest to Thor.
She was created by the late Stan Lee, and the late Jack Kirby, and first appeared in Journey into Mystery #102 in March of 1964.
In the Marvel Cinematic Universe, she is a supporting character in Thor (2011), and it's sequel, Thor: The Dark World (2013), and a supporting character in Agents of S.H.I.E.L.D. She appeared in one episode of the Disney+ Loki tv series, and is returned in Thor: Love and Thunder (2022).
She is portrayed by Jaimie Alexander, who also played Jane Doe in Blindspot.