Typically, when researchers decide one's activity level, they measure only leisure-time pursuits. So the nurse and waitress who log three miles a shift and go home and put their feet up are classified as inactive, because the walking is not on leisure time. To King, Castro, and Brownson, that seemed like a flaw in methodology. Not being around people who exercise deters one's own activity. Two-thirds of older women prefer exercising alone, not in a group.
Activity decreases with age, increases with education level.
When Susan Henry spent time in Alaska, she saw women carry water, wash clothes by hand, and walk miles, since villages did not then, and generally do not now, have roads or vehicles. FitnessLink was puzzled that those women were considered inactive. As your thoughtful question shows, a lot more work needs to be done concerning the every day activities undertaken by many women which they may not have reported. Women living in hilly terrain exercise more than do flatland dwellers. Urban-area hillsides tend to be occupied by the more affluent.