Buffy the Vampire Slayer, Season 5

Buffy:
Are you okay? Did she hurt you?

Dawn:
Why do you care?

Buffy:
Because I love you, you're my sister.

Dawn:
No I'm not.

Buffy:
Yes you are. [holds Dawn's hand] It's blood, Summers blood, it's just like mine. It doesn't matter where you came from, or how you got here, you are my sister. There's no way you could annoy me so much if you weren't.

...

Buffy:
I have to get you back home though, Mom's freaking out.

Dawn:
Oh, is she mad about the whole fire thing?

Buffy:
I think you sort of have a "Get out of jail free" card on account of big love and trauma.

Dawn:
Really? Okay, good. Do you think she'd raise my allowance?

Buffy:
Don't push it.