It is possible (I don't actually know in your case) that there are other factors that make women not want to apply to your company. For example, right now (and in the US) women are more likely than men (for this argument it doesn't matter whether it is cultural or innate) to seek companies that reward people (or at least don't punish people) for wanting a balanced between work and home. A company's career website (or benefits website) can turn off potential applicants if it looks like that balance is not respected. That is particularly true in software because there are software companies that do both.