There is no definitive answer to this question, as it varies greatly from person to person. Some women may sleep with only a few men before marriage, while others may sleep with many more. There is no correct or incorrect number of partners to have before marriage; ultimately, the decision is up to the individual woman.
That being said, a recent study conducted by researchers at the University of Utah found that the average number of sexual partners for women in the United States is seven. This figure includes both heterosexual and homosexual encounters. The study also found that women who had slept with more partners were more likely to report having had an unhappy marriage than those who had slept with fewer partners. Again, though, it's important to remember that there is no right or wrong answer when it comes to this topic - it's entirely up to the individual woman.