Why do women don't practice their serve???
For those who have been to women versus men tourney, Ithink you can see the difference; Men spend at least 45 min practicing their serve while women rarely do; they only practice their groundies and practice their serve only when they do a practice match. IMO, that's why their serve is weaker and you see so many breaks.
The only women player I ever saw really practicing her serve is Shaughnessy, she went to a court by herself with a big bucket of balls and practice for more then 1hour.