Sometimes I write things in stories that I know the readers are going to question. For example, if a character seems out of place in his or her occupation, or if a female character has traditionally male attitudes.
We often meet real people who seem out of place in their role, or who break the stereotypes of their gender/class/nationality/race etc. It's just the way the world is. (And thank goodness for that!) But when we meet a character in a book who seems out of place, we tend to fear that the writer has made a mistake. This can spoil our enjoyment of the novel.
One way around this problem is simply to have one of the other characters voice the question that is on the readers' minds. "I'd never have thought someone like her would work as a clothes designer!" After that, the reader knows, on some level, that it isn't a mistake. It is a quirk of the individual. So the bubble of believability does not burst.