" boys offered to cut back on clothing changes to reduce the amount of laundry. "
Which was how no small number of households managed until affordable fully automatic or even semi-automatic washing machines came along.
Even in a wealthy household laundry bills could be excessive. Someone had to pay laundresses, maids, or a service to do all that washing.
Just bed, table, bath and personal linen (undergarments) per week amounted to no small number. Then you had shirts, blouses, socks, etc...
To cut down on the wash/laundry bills people wore garments (including their underwear) more than once before it went to the wash.
Remember also large families were the norm rather than exception well into the 1970's. Mrs. Kalliak would have had plenty of company being the mother of several kids. IIRC Maytag was another who frequently used advertisements showing large families.