You hit the nail on the head.  Even when in white color jobs where, at one time, all my staff were women, no one one wanted to work after 5 or weekends.  Each one had something they "had" to do.  I had one staff member who worked part-time to accommodate child care.  She once wanted to take her other child to the dentist during work hours because it was tougher when the other child was home.  Then another volunteered at an elementary school.  And another always wanted to take off early to do stuff with family.  Well, I wanted to take time off to do things too, but I never could, as all the women in my office were already off and by God, someone had to do the work.  But let me tell you, they never did forget to tell me how much they did and how hard they worked when it came time to raises.  And honestly, it was easier to just give them a nice raise so as not to have hear the pay gap bullshite.