After which Rosa goes home to bed, and I can't say I blame her. But we're clearly not done with Lisa yet.
The next morning (or night, or whatever it is), return to Lisa. She won't let Rosa in or even talk to her, so it's time to send in the dead guy.
Joey finds nothing in the consulting room, so head right through the door to find the living area.
Here, Lisa is looking at a photograph. Look at it; it's Danny Marconi, the old man in the nursing home. So ... I wonder if Danny can tell us anything about Lisa? Go back to Seagram --
-- and find that the common room is now empty. More, if you talk to the receptionist, you'll discover that Danny passed away that very day. Well, that means Lisa is the only person who can tell us what the connection is.
Go back to Lisa and have Rosa buzz her, then try to talk her way in. Mention Danny Marconi, then ask Joey for help. That does the trick (and is a little startling too).
Inside her consulting room, Lisa is clearly massively scared of a group she refers to as "them." She gives you the names of the last two people she sent to Gavin: Tiffany Walters and Jamie Graham. Find out what happened to them, she says, and I'll tell you more.
You can do them in any order or simultaneously. When you discover what happened to them, come back and tell Lisa.