Comment on Mad Daughter by xCastra
I wish she's not a Crazy doctor like her dad ._. ...
Nothing has been said for sure, although it has been heavily implied.
However, if you want to have anything headcanon based: some fans (including me!) seem to think that while Aya grew up to be very similar to her father, Aya's reasoning for doing what she does is entirely different. Instead of being "mad" like her father was, Aya believes putting people into "eternal sleep" is a way to help them. After all, when she was a kiddo and in the house haunted by her mother's curse, Aya helped all those cursed corpses to afterlife (thus the belief of thinking death means end of suffering)!
But, like I said, it's heavily headcanon-based and therefore can't be taken as the canon truth.