Samara Morgan from The Ring is biologically related to Sadako Yamamura from Ringu
According to original Ringu novels, especially Loop and maybe S, Sadako is a construct of a Loop computer simulation and has multiple clones, which can interact with the real world. In addition, all film adaptations about her life story are cursed which I’m guessing only applies if each Sadako variant, or clone, is “real”.
I believe that Samara Morgan herself is one of those very clones and it can explain why she simultaneously has a more Japanese onryo-like appearance in contrast to the other ghosts in the American Ring movies, who align more with the western conceptions of ghosts including Evelyn, despite being kidnapped and raped for months, and is also more ruthless than the OG Sadako even before death. She’s desperate for an apocalyptic rebirth at this point.
I also theorise that Samara being a product of rape in Rings is the result of Sadako’s clone expressing her rage over being raped and thrown in the well by having others be in her shoes somewhat (ie influencing/possessing Burke to forcibly impregnate Evelyn??). Trauma is cyclical in onryo-centric narratives after all.
Btw, this is my cursory understanding of the lore of the novels. Anyone who has fully read the novels is free to correct me.