The first time Joey talks to the ghost, she's really confusing and almost monosyllabic. The only coherent thing she says is that her name is Mary. Probably.
If you look around this room, you'll see something on the floor that Joey describes as a small plastic thing with a metal bit on the end. That doesn't sound like much, but remember, Joey's frame of reference is the 1930s. It might be something really important that he just doesn't recognize.
The "plastic thing" turns out to be a memory stick. Pick it up, and Rosa will use it on her phone to download a photo that Joey recognizes as the ghost upstairs. We need to do some more research to find out her name, though.
The photo caption says "Gotham Collective." Try typing that into the research area of your phone (click on the magnifying glass icon and type in the thing you want to search for).
This yields the information that the Gotham Collective was a theatre troupe that went out of business some time ago. The website includes a downloadable text file called "GC_CastAndCrew.txt." Sounds useful. Click on it to download it to your phone.
Now it's time to use the notes function to combine two ideas.