When a ESOL test is taken, a subject topic is chosen in order to test the speaking and listening elements. Topics can be anything the examiner picks, ranging from talking about holidays to transportation etc.. The topic for your wife had been Life in the UK as a chosen topic, this is not the same as the Life in The UK being built in, just a topic to talk about in order to assess the English, nothing more.
Have a look at the link below, this is a list of acceptable qualifications the Home Office will accept and see if the ESOL is within the list:
https://www.gov.uk/government/uploads/s ... _tests.pdf
As you have discovered, your wife will need to take the Life in the UK test in addition to the English test already taken. You can search to see if the contents of the Life in the UK can be studied in a different language if that helps, but do note that the test needs to be taken in English. You can also request to listen to the questions at the test centre in addition to reading them, this may help further.
You should also note that though there are many practice questions out there, no one has access to the actual questions that are in the actual test, so memorising the answers to the practice answers will do no good. My Mrs did the test recently and the questions were completing different even to the official practice questions and answer book by the test organisers. Its better to learn key dates and events and I would recommend your wife study from the official life in the UK book 3rd edition first, then attempt practice questions.