Fair to ask if the spawn of incest.
Her sister.
Both
That brother, who moved to London long ago, was and is a FLAMING HOMOSEXUAL; hence, no way did they have sexual congress.
Evelyn Mulwray: She's my daughter.
[Gittes slaps Evelyn]
Jake Gittes: I said I want the truth!
Evelyn Mulwray: She's my sister...
[slap]
Evelyn Mulwray: She's my daughter...
[slap]
Evelyn Mulwray: My sister, my daughter.
[More slaps]
Jake Gittes: I said I want the truth!
Evelyn Mulwray: She's my sister AND my daughter!
Forget it Jake, It's Muzzietown.