Beth was the patient who Wilson was introducing to Cameron to get her to prescribe her narcotics. She is portrayed by actress Mandy June Turpin.
Wilson's privileges for prescribing narcotics had been suspended thanks to Michael Tritter putting pressure on him to turn on House. House "generously" agreed to let Wilson have Cameron to do his prescribing in the meantime, but Cameron insisted on meeting with his patients before prescribing any medication.
However, when they met with Beth, she was confused about why Wilson couldn't prescribe her medication anymore, and Wilson couldn't let her know about the suspension. She guessed, incorrectly, that Wilson had somehow screwed up her medication despite Cameron insisting that wasn't the case.