Her work starts at 10am, which is the same time the library opens to the public.
Every day, she arrives slightly after 9:25am. As she was not issued any security pass, she will stand outside the door and wait for one of the staff inside to open the door for her.
When a staff does not see her, she will just wait till 10am when the library opens.
Even when she sees a staff inside, she does not knock on the door to get the staff attention and open the door for her. She will just wait till someone sees her and comes open the door.
Sometimes, when staff from other departments or cleaner with access pass enters the library, she didn't make use of the opportunity to go in as well. She will just obediently stand outside and wait for the staff inside to let her in. And she will not ask the security guard for help to let her enter the library with his access card.
There are so many ways she could have got into the library. Why did she choose to wait till someone sees her? Is she afraid? Of what? Is she introvert? Was she instructed to do so?