So it means they have to sit the exam.If she was 54 when she applied, then she does need to take the test and interview both.
http://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=374&top=5
Who has to take the citizenship test?
Everyone between the ages of 18 and 54 at the time they apply for citizenship must take the citizenship test. We use the test to determine if you have adequate knowledge of Canada and the responsibilities and privileges of citizenship.
If you are 55 or older when you apply, you do not have to take the test. If you turn 55 during the processing of your application, you still have to take the test since you were under 55 when you signed your application.
Thank you