As I'm sure your aware from discussion of Kings blood. If you go back far enough everyone is related. An I am talking earliest history.
Ah ok, yeah maybe a supernatural ancestor way back at the beginning...
I still think that magical talent is a fundamentally 'human' thing though. I think there is a difference between how the series portrays wizards/magical practitioners vs. scion-types (Changelings, WCVs, Red Court Infected, etc.) who have some sort of 'Choice' mechanic or bifurcated nature.
Molly is pretty easily explained. When she actively used magic it actively made her cells reproduce closer copies, an effect that clearly does not continue when you stop using magic. So her cells were literally suffused with magic when Molly was concieved.
Yeah I think that's probably about right. There probably
is a genetic component but active use of magic and the biological effects of it also play a large role.
IMO this is why magic is 'usually' inherited matrilineally but not 'always'. Genetics + prenatal environment are far more likely to push someone above the threshold where their talent manifests obviously, having the Sight, etc. than genetics alone.
But in the really strong lineages like Eb/Harry you don't need both. Charity was a quite weak talent.
An if it's not inherited than the WCV'S actions in WK have absolutely no real value.
Oh, I think it's "inherited" just not entirely "genetic", the mother actually using magic (not just having the talent/genes) seems to be important from the case of the Carpenters.
Its all inheritance in the DF, can't think of a single example where someone gets something or has an aspect that's not inherited from somewhere.
What about transfer of power from supernatural beings to mortals? Lash gives Harry Hellfire, Uriel gives him Soulfire, I'm pretty sure Harry isn't descended from angels or Fallen...