Something I never thought of...

[fly on the wall]

I've always thought it was so odd how they introduced the character of Dawn. They just planted her in there without any back story. I think they thought up the Key story line because fans were so confused. All they had to do was phrase it as 'Dawn used to live with their father, but will now be living with Buffy and thier mother..' Thats it, confusion gone.. Instead she was introduced like she'd always been there. It was weird. But, I guess it ended up working out bc of the whole key-mystical-ball of energy deal.

Oh, no, you've got it backwards. They didn't just plunk her into the storyline without warning. We had so many clues that Dawn was going to come. And in fact, they had TRYING to confuse fans at first with episodes like "Real Me." They didn't just dump her there on a whim, realize they were confusing people, and whipped together a convenient story...They couldn't have for a hundred reasons, a major one being whole seasons are written, revised, etc before they're aired.
Dawn just showing up as "having used to live with her father" would have been horrendous. All the mentions that Buffy was an only child, four whole years with NO mention that she had a sister, and then suddenly she's there? A mystical Key isn't likely, but it's far more likely than that..

 

[shaphalf]

What WA said. So technically, no, they never met. Though at the beginning of season 6 Dawn says 'Dad said he'd call' when she wants to answer the phone instead of Buffybot....so that implies they've at least spoken.

But we never saw the two of them on screen- which I don't know whether that would have been interesting or not.

Probably not. I can't imagine that being anything special.