There's a picture of the scene in the bedroom attached to the review. It's obviously Hannah's bedroom. Look at the decoration hanging over the bed and the color of the walls.

Her light bulb moment was her mom's story. She says something like, "Did you get the guy back?" to her mom, and her mom was so consumed by hate that she didn't even care about that. She was just happy the girl was dead.
That's pretty clearly when Hannah realized where she stood and what she was about and decided to…

They were at Hannah's apartment, not Tally's.
Adam and Jessa were at Laird's looking after Sample.

They've been roommates for a few seasons now. I could be misremembering, but I think Adam first moved in with Ray when he was acting and needed time away from Hannah.