Oops - I mean Woody’s adopted daughter. She was not a blood relative either.
She was Mia Farrow's adopted daughter. Woody Allen never married Mia Farrow, he never adopted Soon-Yi, so all Allen was doing was uh-uhing Soon-Yi’s adoptive mother. No family relationship with her until he married her.
I'm not saying there wasn't an ick factor, but ick factor doesn't make it incest.