i dont think that many people are like that really - but maybe she had sex toys, lingerie, dirty knickers etc that she didnt want you to see
maybe there wasnt any, but at that moment maybe she wasnt sure what shed left out
why do you care though? surely if she wants it private then so be it... not sure why you view it as a fault...
i have never understood people who feel the need to give you 'the tour' of their house... i dont mind it of course, and have no issue with it - whatever makes you happy - just not sure why people do it.
unless its of show home standard and amazing, then not sure of the point of being shown round - except to know where the loo is etc
it would not occur to me to do it really.