She's seen just standing and staring at her sister's bed, unmoving, for about a minute and she doesn't wake up until her mom comes into the room.
No one wants to wake up to that terrifying sight. It's not even that she's staring, which is creepy on it's own, it's that she doesn't even flinch - even when her sister is screaming at her and crying while begging her to stop...
We have all been there stuck next to someone you don't know in confined space. Something happens where you can't wait for this unpleasantly awkward situation to just end.