First, we should realize that the role of most women during the Progressive Era was the same as the role of most women before that era and soon after it.  For much of our history, including the Progressive Era, the main role of women was to be housewives and mothers.  This was still a time when this was the role that was most expected of women. 

Second, the roles of women varied quite a bit based on the economic class to which they belonged.  Poorer women typically had to do some sort of paid work in addition to their work as wives and mothers.  This was a time in which many poorer women did things like working in sweatshops so as to help make ends meet for their families.

Having said all this, let us turn to what was relatively new about the role of women in the Progressive Era.  Women were some of the main drivers of some types of reform during this time.  For some time before the Progressive Era, American ideology had held that women were morally superior to men and were the guardians of the moral atmosphere of the home.  During the Progressive Era, this idea was used to justify the idea of women trying to reform society.  The idea was that women should use their moral superiority to reform and protect the morals of all of society, not just of their individual homes.  This led to a situation in which many women from the middle and upper-middle classes became reformers.

Women worked in a variety of reform roles.  Some women worked in the settlement houses where they provided a variety of programs to help reform the ways in which poor people (particularly immigrants) lived their lives.  Some women were deeply involved in the push for Prohibition because they believed that women and children were harmed when men drank.  A few women, like Ida Tarbell, worked as muckrakers, helping to expose what they saw as conditions that needed reforming. 

In all of these ways and more, a certain class of women became a major part of the impetus for reform in the Progressive Era.