She isn’t even Woody’s stepdaughter. He never married Mia Farrow.
Soon Yi is the adopted daughter of Mia Farrow and Andre Previn. She has two parents. Allen isn’t one of them.
You are correct. I forgot that Allen never married Farrow, though they did have one biological child and did adopt 2 together.
So, if may be distasteful, but that’s about it.
This other guy, though, is sick!!