Buffy: Dawn foreshadowing?

[Samhaine]

So, I've been watching the Buffy marathon today (ah, the classic eps) and they've been showing little interviews with the writers/producers/actors. During one, there was a blurb that the writers started to foreshadow the arrival of Dawn in Season 3.

I haven't noticed it in the few eps they've shown, and I can't remember any.

Can anyone think of any examples?

[Nightflower]

The episode where Buffy has a dream and Faith is in it. It's not the one in season 3 finale... Buffy and Faith are making her bed, and Faith says "Little sister's on the way" or something like that. Ah....my memory sucks.