I know this book isn't technically a "children's book," however because I read it when I was so young I ended up re-reading it in college and finding it so much more rich an nuanced than I did as a nine year old girl (obviously, lol). 

Here are some lines that always stuck out to me:

“I declare after all there is no enjoyment like reading! How much sooner one tires of any thing than of a book! When I have a house of my own, I shall be miserable if I have not an excellent library.”

“There are few people whom I really love, and still fewer of whom I think well. The more I see of the world, the more am I dissatisfied with it; and every day confirms my belief of the inconsistency of all human characters, and of the little dependence that can be placed on the appearance of merit or sense.”

“Angry people are not always wise.”

“Pride is a very common failing, I believe. By all that I have ever read, I am convinced that it is very common indeed, that human nature is particularly prone to it, and that there are very few of us who do not cherish a feeling of self-complacency on the score of some quality or other, real or imaginary. Vanity and pride are different things, though the words are often used synonymously. A person may be proud without being vain. Pride relates to our opinion of ourselves, vanity to what would have others think of us.”

“Nothing is more deceitful than the appearance of humility.”

“You shall not, for the sake of one individual, change the meaning of principle and integrity, nor endeavor to persuade yourself or me, that selfishness is prudence, and insensibility of danger security for happiness.”

“You have bewitched me, body and soul.”

"I know your disposition, Lizzy. I know that you could be neither happy nor respectable unless you truly esteemed your husband - unless you looked up to him as a superior. Your lively talents would place you in the greatest danger in an unequal marriage. You could scarcely escape discredit and misery. My child, let me not have the grief of seeing you unable to respect your partner in life. 

Jane Austen