Since I am bad at names, and I suspect others might have also had difficulty remembering the names of the sisters:
The name of the woman you have to call out to during "A midnight stroll." is Penelope.
The sisters in the paintings for "Cracking the case." are, in order, Penelope, Isabella, and Eliza (Black Widow). Make sure you listen to all of Orville's stories before this mission (his stories are true, Eliza betrayed her sisters, so she is still alive and they are ghosts), and if they ask what it explains, give the supernatural answers. And, of course, Libby is the Black Widow, and she killed your father.
I think I covered all the answers, so please let me know if I missed any details. I just had trouble with the names, but since there are a lot of responses that have to be correct or the mission fails, I figured I should list the correct ones and the unstated mission requirements of listening to all of Orville's stories.