The test might be conducted orally as well.
@O'canada had this experience where the test was conducted orally over MS teams. May be the OP can help you with any information you might need
Yes some applicants are receiving Oral Citizenship test, where the case officer will meet you in MS Teams and you are given the same time ( 30 mins ) to answer the question ( 2o Questions).
You will be answering questions as soon as the questions appears on the screen ( Case officer shares the screen ). And you are given time to review at any point of time during the test.
After the test you will be interviewed ( Its not related to test) but in general about you timelines, Job, Etc.
As your wife missed the first attempt of the test , Please let us know how it went the interview as mostly I guess they will ask her knowledge about Canada
I don't know why she was not given second attempt to write the test,
Here is the source