Hm, you write well, but one of your main problems that I can see here is tell and not show.
Here, let me explain. Right in, you say she was frustrated. SHOW she was fustrated. ie, make her flick her hair, stamp a foot or something.
And you say she can detect lies, you could show that through dialogue: "..." (person says a lie) and then her eyes narrow, "You're lying" but oh no, she couldn't say that because she's a nurse.. and blah blah so on.
Well, hope i was of help :)

Narq.

Woah. . . it reaelly sends a chilling sensation down my spine. . .Nice work ;)