@@ I was allowed to take a sip of my parents' wine if I asked when I was about 6. I can't remember the exact age, but I know that, if we were having wine at dinner at home, I was asked if I wanted a glass by the time I was 14 or 15 or so. Have not yet turned into an alcoholic.
It's legal in Wisconsin. You can drink at any age when accompanied by a parent. In practice, not a lot of bars will set you up with a boilermaker, but the law is on your side. Letting your kids have a sip of champagne at brunch is not going to ruin their lives.