(SPOILERS) Easy to miss disturbing secret in Fatal Frame 5

[curl-6]

Boberkun said:

curl-6 said:

Elsewhere in the game, we discover that her mother, Miku, entered into such a ghost marriage with her dead brother, Mafuyu. (Those who have played Fatal Frame 1 and 3 will remember his story)

Where exactly? During the first pass I've tried explored every corner of each location and don't remember any notes about that. 

In the cutscene where Miu finds her mother in the requilary, touches her, and sees into her memory.

The ghost of the old lady also says as much in the scene right before this, when she calls Miu "Shadowborn", and tells her "the person you are looking for has entered into a ghost marriage".