IR Enquiry

Hello.
We are dealing with an enquiry at the moment. I am happy with everything, but two things are niggling me as i have not been asked for this before.
One is they want the wifes bank statements. She is not a partner or part of the business, and no business funds (in or out) have gone through her account. She earns more than the husband and so she pays most of the house bills. Can the revenue insist on having them? She is reluctant to get involved. nothing dodgy, she just does not want to get dragged into her husbands problems (long story). The other is they have asked lots of questions about lifestyle etc.. but they have even asked about childrens school dinners! is this going too far? even wanting an estimate of how much would be spent on the bread to make sandwiches for school lunches?! It is feeling more like market research than tax enquiry!
Thorough?
Thanks ladies and gentleman.

David