For the earl daughter you need to :
- talk to every contestant and servant
- then talk to the "old man #43" just outside the mansion
- then notice the potion on the daughter altar
- look at the clock need the servant and find the paper
- talk to the servant about it
- investigate the book the servant tells you about (a closed light brown book on the left side of the room iirc)
- search the room of the current earl (the left one second floor)
- talk to the cousin
- talk to the earl (son)
- hide in the earl empty closet
- search behind the bed
- go to the altar potion again
- talk to the daughter again
- go to the basement
- use the piano
The last steps are a bit fuzzy in my mind so I may have forgot some steps, but if I forgot any they should be straightforward
Also some steps are probably useless but it's all I can recall doing.
@OP :
There is a bug at the stronghold south west of the map that makes completing it impossible.
The issue is that a image is not found inside the package of the game (ver 033b)
It can be easily fixed by creating a folder "Graphics" then "Faces" and putting a standard portrait image from any RPGM game inside it and renaming it Actor30
Maybe it's worth putting this workaround in a spoiler in the description until the bug is fixed.
Also there is gender bending and even transformation (hell's barder)