Then just think of her and these others as imposters:
Part of a documentary crew brought to Asgard by Loki, Roger "Red" Norvell meets and falls in love with Lady Sif. Red Norvell is given Thor's Iron Gauntlets and Belt of Strength by Loki to compete with Thor for Sif's affections, beating him and taking his hammer, with neither realizing this was part of a master plan by Odin to create a surrogate God of Thunder to die fighting the Serpent of Ragnarok and fulfill the prophecy.
Beta Ray Bill
Beta Ray Bill is the champion of the Korbinites, an alien race. Debuting in Thor #337, the character was initially intended to be a surprise as an apparent monster who unexpectedly proves to be actually a great hero. As such, Bill becomes the first being outside of the Marvel Universe's Norse pantheon to be deemed worthy enough to wield Thor's hammer, Mjolnir. After an initial rivalry for possession of the weapon, both the Thunder God and the alien warrior reconciled as staunch allies. Bill is granted a war hammer of his own called Stormbreaker, which grants him the same powers as Thor. He has since made numerous appearances.
Eric Masterson is initially bonded with Thor after Thor is punished for apparently killing Loki. Masterson carries the mantle of Thor for several years, continuing his roles as a member of the Avengers and protector of Midgard. Thor is eventually freed from Eric's mind, and asks that he continue serving as God of Thunder. Tricked by the Enchantress Masterson attacks Thor, and soon after relinquishes the hammer to Thor. In gratitude for his services, Odin provides Masterson with an enchanted mace, which he uses under the alias of Thunderstrike.
Dargo Ktor is the host of a 26th-century version of Thor, who is empowered when holding Mjolnir, a subject of worship in that century.
Marvel announced that in October 2014 there will be a new Thor who is female. As revealed in the aftermath of the "Original Sin" storyline, Thor lost his ability to wield Mjolnir, which was later found by an unidentified woman who obtains both the Asgardian's power and name.
And these are all from the mainstream universe, there are many more in the parallels.