No, Thor and Hela do not share the same mother in the Marvel Cinematic Universe (MCU); Hela is Odin's firstborn from a previous conquest, while Thor's mother is Frigga, making Hela Thor's half-sister, though her mother's specific identity (possibly an unnamed giantess or different goddess) remains a mystery, deviating from comics where Loki is Hela's father.
The identity of Hela's mother wasn't revealed in the film, but as it turns out, she's actually Thor's half-sister, as she isn't the daughter of Thor's mother Frigga.
THOR HAD A SON WITH HELA, BUT HE KILLED HIM Modi Thorson was Thor's son in the Ultimate Universe (Earth-1610), born from Thor's deal with Hela to save Valkyrie. Raised by a villainous Loki, Modi grew to resent Thor.
Thor got hela pregnant and had a son name modi thorson. In the mythology she is the daughter of Loki as well. That was a weird twist, but it being sibling rivalry wasn't too bad.
Hela is the child of Loki, God of Mischief, and the giantess Angrboda.
Saxa's name refers to that of the giant Járnsaxa. According to Poetic Edda, the first book to be recorded by Völuspá (the seer's prophecy about Ragnarök), Járnsaxa was Thor's lover and had a son with him, Magni.
Magic: Hela has gifts for magic, being able to manipulate it in her form of Asgardian magic. Upon earning her crown for her act of mercy with Odin, Hela received a wide range of Asgardian magic that transformed her robes into white armor and allowed her to contain and redirect Odin's energy attack towards himself.
Thor was married twice: first to Iarnsaxa and second to Sif. He had 3 sons and 1 daughter from these 2 marriages. He did not kill any of his family. In this respect he is nothing like Herakles who was promiscuous and uncaring towards his wives.
She preyed on his fear and desire for power, molding him into a tool for her evil deeds. Once she assumed the throne, Hela destroyed the murals in the palace that depicted Odin's reign of peace.
Lorna Dane continued to appear in The X-Men, now retitled The Uncanny X-Men, as well as a new series simply titled X-Men (no "The"). In The Uncanny X-Men #431 (November 2003) a DNA test proves that she is the daughter of Magneto.
Hela was also extremely resentful of her imprisonment at the hands of her own father, Odin, whom she was initially loyal enough to willingly execute his will, and even help him conquer the Nine Realms, although she would eventually rebel after Odin grew to become a benevolent king.
Lorna Dane is the daughter of the infamous Magneto. Inheriting her father's mutant abilities of magnetism, she adopted the name Polaris. She has explored very diverse paths concerning her stance on mutant affairs.
With Sif, Thor fathered the goddess (and possible valkyrie) Þrúðr; with Járnsaxa, he fathered Magni; with a mother whose name is not recorded, he fathered Móði, and he is the stepfather of the god Ullr.
She is the child of Odin (albeit a different incarnation who died during a previous Asgardian Ragnarok) and the giantess Angrboða. When she came of age, Odin appointed her as the Goddess of the Dead, giving her rulership over the dead in the realms of Hel and Niflheim.
As the first major, openly gay character created by Marvel Comics, Northstar generated significant publicity in the mainstream press, and Alpha Flight #106 sold out in a week, although the series was not a very popular title.
And much like the grim reaper, Mistress Death's true form is a skeleton but she can changed into a woman (if so desires) and if anything happens to her (like being captured) then death itself would stop. Thus, in the comics Thanos actually falls in love with her and wants to prove his love to her.
TL;DR Odin's enchantments are what makes Mjolnir nearly unbreakable. When Odin dies his enchantments are lifted, allowing Hela to easily crush the hammer.
Four gods, Thor, Baldr, Víðarr and Váli, are explicitly identified as sons of Odin in the Eddic poems, in the skaldic poems, in Saxo Grammaticus' Gesta Danorum, and in the Gylfaginning section of Snorri Sturluson's Prose Edda.
Magni, Modi, and Thrud are part of the Last of the Aesir Magni is the Norse god of strength. He is the son of Thor and the giantess Járnsaxa, and the brother of Móði. He is reputedly the strongest god in Norse mythology, even more than his father.
Loki seduced/tricked Sif into sleeping with him, and then cut her hair off so that Thor and everyone else would know that she had been unfaithful.
Sif is the wife of Thor and the daughter of Odin and Freya(Frigga.). Freya is Thor's mother and Odin's wife. Let it be stated for the record. And yes some emanations of Sif are Thor's wives and some emanations of her are his sisters.
The enchantment, however, held that if Mjolnir left Thor's grasp or was removed from his person for more than 60 seconds, both would revert back to their mortal states until they were reunited.
Valkyrie is an Asgardian. She was part of a legendary force of women warriors that seemingly all perished. When Odin ordered the Valkyrie to drive his daughter Hela, the Goddess of Death, into a prison of Odin's making, she alone survived the assault thanks to another's sacrifice that saved her.
Hela is just a Goddess of God of the Norse Pantheon in the MCU, She's just one of many Gods of Death there is. Whereas Rio Vidal is the Literal Aspect of Death itself. Rio is Death. She is the embodiment of the concept of Death.