Wie's official LPGA biography lists her at 6-feet tall - six feet even. But she is believed to be a bit taller than that, with some sources listing her as tall as 6-foot-3. However, the most commonly accepted figure is that she is 6-foot-1.
It's not uncommon for athletes' heights (and particularly weights) to be fudged by their teams, by their leagues, or by the athletes' choosing. Some athletes prefer not be listed as tall as they really are; others prefer to be listed taller than they really are. (This is probably most common in the NBA, because height is so integral to how basketball players are viewed).
Wie being listed at 6-foot-even by the LPGA is likely something done at Wie's request, although that is speculative. It's clear from comments Wie has made over the years, however, that she wishes she wasn't quite as tall as she is.
So while the LPGA says 6-foot, Michelle Wie's height is actually believed to be 6-foot-1.
Wie is believed to be the tallest player on the LPGA Tour, although the tour does have other 6-footers (Anna Nordqvist, for example). The question of Michelle Wie's height was a common conversation piece especially early in her career, because she was so tall at such a young age. She was nearly 6-feet tall by her mid-teens.