This could just be an artifact of the way Prometheus was cut for theaters but it seemed to me that any normal person after having gone through what Shaw had, the surgical removal of an alien monster from her body, she would mention this to someone else.
Instead she just suits up and runs to join the others. Vickers might have found the fact that her section of the Prometheus now has this monster in it of some immediate interest upon her return.
Perhaps some other cuts indeed have Shaw mentioning what had happened to her? I realize that Vickers would have been angry at Shaw for using the device but Shaw is an adult human, not some little kid worried about being punished -- obviously the entire crew is jeopardized by the trilobite although perhaps also Shaw thought it was dead and/or it was pretty small and not as dangerous looking as, for example, Fifield was.
