I was pondering that the other night. I wonder if the family used her email address to have the password reset or possibly they were able to easily access the account and they shut it off. Or somehow LE or the family contacted FB to request the activity to be halted or to gain access to it if they couldn't retrieve the password themselves. Or as you mention it becomes inactive after 30 days of inactivity.
It always spooked me a little when two people attempted to make contact with her by posting a comment, the game app was still active at the time. The game app. appears on the account as if the person is actually playing it. Possiblly the two people (one was her brother) are not aware of that and thought it was possible KL was playing a game.