Lydia emphasis her speech a lot

Oh! yes (chpt 9)
Look here
Well, now
I do so want
"What do you think?
excellent news -- capital news
Well, but
There's for you!
I will answer for it
Lord
(chpt 39)

Lydia also uses rhetorical questions a lot:
What do you think has happened this morning? (chpt 20)
Is not this nice?
What do you think?
is not it?
who could about such a nasty little freckled thing?
Have you seen any pleasant men? Have you had any flirting? (she doesn't wait for an answer)
what do you think we did? (chpt 39).

I should have done more grammar at school. Lydia's constructions often seem slightly off:
would like to go too of all things!
There's for you!
My aunt Philips wants you so to get husbands, you can't think.
only think what fun! (chpt 39)

And of course:
Kitty and me (chpt 39) (I know enough about grammar to say it should be Kitty and I. And yes, I also know about all the philosophical problems in saying what grammar is right, I just highly suspect that JA knew how the "me" would be regarded by her readers).

I love this line:
And we mean to treat you all," added Lydia; "but you must lend us the money... (chpt 39) - no asking here but just demanding. Followed by:
when we got to the George, I do think we behaved very handsomely, for we treated the other three with the nicest cold luncheon in the world (chpt 39) Spoiled child anyone? Careless towards others?

Another sign is in chapter 9:
And when you have given your ball," she added, "I shall insist on their giving one also.

Kitty's speech is comparatively better, there's nothing blatant like "Kitty and me".
"I do not cough for my own amusement," (chpt 2)
"I cannot see why Mrs. Forster should not ask me as well as Lydia, (chpt 41)