I don't speak whine-ish

I need some motherly advice.  My oldest and I butt heads ALL. THE. TIME.  Probably because she is very much like me.  One thing that we are working on (and have been working on since she was born) is her whining.  I hoped she would grow out of it by now (I mean, come on, she's 7) but that's not happening.  I've tried all sorts of things from telling her to "rewind" and say things again in a better tone, to telling her that I don't speak "whine-ish" and ignoring her, to giving her "sassy sauce" (vinegar water) when she does whine.  Nothing seems to be working.  Does anyone have any suggestions?  This could be a LONG summer if I can't figure something out.  I want to nip it in the bud now because I worry that she'll turn into a very sassy teenager.