That means women working full-time jobs - on average - get $13,842 less per year for doing the same work. If you earn less you save less, to me that is common sense, but this one factor is not considered in the above information.
This means that the more of the total amount of income coming into their home must be spent on everyday expenses, which leave less for savings of any type. Increase income, and you increase the amount you can save. Pay equal rates to men and women and the problem will be solved. Women earn less and therefore save less then men, fix the inequality of wages to fix the issue.