I had the same reaction back then. A person really doesn't want to entertain such a thought.
Frankly, it is too dark to even entertain now.
I choose to believe there is some other dysfunction at work.
Still, I would not be completely surprised if someday a book comes out from one or both of the daughters, when they become adults.
She inherited being on the Autism spectrum from her dad. Nothing more than that.
Check this out -
He is looking at the camera and she is kissing an imaginary stranger over his left shoulder.