Buffy the Vampire Slayer, Season 6

Dawn:
Oh, come on, Tara. I am so old enough to do research. Do you really think I'm not mature enough?

Tara:
I think you're very mature for your age ... but you're still only fifteen.

Dawn:
Right. Fifteen, as in teenager. You know, if you don't let me look at the pictures, I'm gonna learn everything I know about demons on the street.

Tara:
[sighs and hands Dawn a book] Knock yourself out.

Dawn:
Thank you. See? No biggie. I can totally handle it.

[Dawn opens the book to the first page]

Dawn:
That's a weird place for a horn... [stares at the page, then closes the book, shaken] That's not a horn.

...

Buffy:
[seeing Dawn doing research] You do research now? Would you like a cappuccino and a pack of cigarettes to go with that?