She may or may not have had a family, scripture says "household", which could be family, could be servants. At any rate, it wasn't unheard of to have women doing things besides cooking and cleaning. Women as we know, traveled with and supported Jesus and Paul. Martha's sister Mary, "chose the good part", became a disciple as did other women. We Protesant types don't have a domestic meltdown just thinking about it either. :)
I don't disagree. The point is, whatever exceptions you can point to, Mary's betrothal was also commonplace, or the Protoevangelium would not be describing it so matter-of-factly.