"Lady Middleton... did not really like [Elinor and Marianne] at all. [T]hey neither flattered herself nor her children... and because they were fond of reading, she fancied them satirical: perhaps without exactly knowing what it was to be satirical; but that did not signify. It was censure in common use, and easily given."
-- Sense & Sensibility
In Emma, Mr. Knightley tells Emma's former governess: "She will never submit to any thing requiring industry and patience… Emma is spoiled by being the cleverest of her family. At ten years old, she had the misfortune of being able to answer questions which puzzled her sister at seventeen.” In Northanger Abbey, Eleanor and Henry Tilney talk with Catherine Morland about reading history books as well as novels.
More broadly, there are references in Austen to girls going astray, either through not learning enough, or from learning the wrong things. Lydia Bennet is "vain, ignorant, idle, and absolutely uncontrolled," and Elizabeth begs her father to step in and correct her. Marianne in Sense & Sensibility is too indulgent of her wild sentimental feelings.
Anne Elliot of Persuasion seems to have her head screwed on straight. Her education furnishes her with quotes from the best poets and essayists for contemplation and consolation. In Mansfield Park, as we've been discussing, there are more explicit remarks from Austen about education than in any other of her novels.