I'm glad you are enjoying so far ^^ I put some guidance below, but you're free to ignore if you'd rather figure it out for yourself.
After visiting the ghost house, there's another location you need to go to, to find the other ghost NPC... said location isn't accessible from the start of the chapter though, you have to open it up.
(And, for a more direct answer):
You have to open the red doors directly right of Lorena's house. If I remember correctly it goes something like this
North of the church, interact with the bug and get the drawing, show that drawing to the human artist, take his watering can, give it to the invisible girl who stands next to where the frog was. you can use the item you get from her to open the red doors and progress further.