"Game of Thrones" fans have come with a new theory, which speculates that Meera Reed, who along with her brother Jojen leads Bran to the Three-Eyed Raven, is Jon Snow's twin sister. 

The theory is based on the speculation that Jon Snow is the child of Rhaegar Targaryen and Lyanna Stark. But Lyanna did not just give birth to Jon in the Tower of Joy before dying, instead she gave birth to twins – a boy and a girl, the theory speculates.

According to the theory, when Ned Stark attacked the Tower of Joy to free his sisters, the only other survivor besides Ned was Howland Reed, Meera's father. The twins were supposedly separated to protect them, and Meera was given to Howland.

"What if Ned had Howland take Meera back to Greywater Watch to raise Meera as his own and Ned took Jon back to Winterfell to raise because bringing two bastards back would seem suspicious?" the theory posted on Reddit questioned.

Another Reddit user also posed the same question nearly two years back, writing: "Howland certainly owes Lyanna a debt, which we know thanks to the story of the Knight of the Laughing Tree. Him taking a second child and hiding it at Greywater Watch could certainly have happened in the time between the TOJ and Ned returning to Winterfell… Is there a more perfect place to hide someone who doesn't want to be found than Greywater Watch?"

The Reddit thread also pointed out that Meera's physical attributes are similar to the other Starks. For instance, she is slim and flat-chested like Lyanna and Arya and she is considered attractive, but not traditionally beautiful. Like her alleged mother Lyanna, Meera is also said to have a fiery personality.

Another fact that's being used to support the theory that Jon and Meera are siblings is that the two appear to be of the same age.

"Game of Thrones" and the sixth book in the "A Song of Ice and Fire" series will be released in early 2016.