She doesn’t want to go up the hallway because there isn’t an easy way to exit, so she picks the door next to the guard’s room.
After making sure no one is inside, she enters.
It appears to be a surgeon’s room combined with a doctor’s office. There is an operating table in the center of the room. It is luckily clean.
There is also a sink, a desk, and a cabinet. There is also a cart with a doctor’s bag sitting on top of it.