Ridgewell:
Mr. Clarkson just returned from an expedition after two years - and his pretty young wife has nothing better to do than go and see a variety show without him?
It could be a subtle hint by Herge that in two years she has developed a life of her own :).
On the other hand, when Tintin reads of the expedition's return to Europe in the newspaper, it means that the members have already been back in Europe for at least a day or two. No sooner are they back that they have a lot to do, such as submitting reports and contacting various museums and other interested bodies about their discoveries. In Clarkson's case, he would have to develop the photos and films that he took during the expedition. He would probably have spent the night of his return with his wife, catching up, but then would get to work. In the original French version, the Thompsons later tell Tintin that one of the victims was at his "table de travail" (work desk) and that could have been Clarkson.
Ridgewell:
Women in general aren't a big thing in Tintin books, and if I'm not horribly mistaken, Mrs Clarkson is the only one that would pass as attractive in the whole Tintin universe.
In the early 20th century, adventure comics featuring male heroes were seen as aimed mainly at boys and it was not considered proper to have many female characters in such comics. Published today, Tintin might have a girlfriend but indications that a male hero was having intimate relations with a female character outside marriage was something that was discouraged at the time. Thus most female characters were restricted to landladies and housekeepers who were shown as middle-aged.
It was not until the 1960s that this rule was relaxed and women started to appear regularly in such comics, a good example being Bianca Castafiore who became a more important character in the latter books. Female characters even became the stars of their own series, being shown as just as adventurous as Tintin himself.
