If the game is about the player investigating the events going on at the lady’s house, the lobby could be the player’s room with your typical dark ambiance, and a corkboard full of pinned clues, information, and maybe even a few witness accounts.
For a bigger multiplayer game though, I feel like you wouldn’t be able to fit that many people inside a tiny bedroom so you could switch it for a police station (assuming the player works there and that they were asked to investigate the place by a neighbor who claims to have seen/heard suspicious activity), or a spacious basement that a group of friends could use as a “base” (same idea still, with the corkboard and stuff).