Yuki's AKB600secs episode reveals that she speaks in a Kagoshima dialect when talking with her mother. I can't distinguish much of a difference from what was shown, but that's what the text says when she's picking out ketchup. I believe the phrases "Kechappu dorega ii
ke? Mittsu ookisa ga arukara
wakannaigayo" (ケチャップどれがいいけ? 3つ大きさがあるから 分かんないがよ) differ from standard Japanese. And I think she said the word "wakannai" with an accent. She usually pronounces that word more "normally" when doing AKB work. Kind of amusing to me.
Here's another bit of info pertaining more to the interests of this forum. It's common knowledge that Yuki admires Ishikawa Rika. You can see her wearing H&A gear sometimes. It's also common knowledge that Yuki hates birds, especially pigeons. Yesterday, she made a blog post about seeing a pigeon and that made me wonder if the two are somehow connected.