In chapter 14, Jane Austen speaks directly to the reader: The advantages of natural folly in a beautiful girl have been already set forth by the capital pen of a sister author; and to her treatment of the subject I will only add, in justice to men, that though to the larger and more trifling part of the sex, imbecility in females is a great enhancement of their personal charms, there is a portion of them too reasonable and too well informed themselves to desire anything more in woman than ignorance.
Catherine Morland is still a teenager (17 years old), while Henry Tilney is already a pastor and he probably graduated from a college. Women in England did not receive much education 200 years ago. Also, Catherine has good sense and honesty.