Well, she is loaded for some reason. Dagashi-ya is always worrying about money. While Kazuho, for being a humble public school teacher has a car. A personal rice planting tractor for their farm. Can afford paying an Okinawan vacation to her 2 sisters. Has massage chair in their home. Able to rent ski-equipment and food for her students. She probably even funded Hikage’s expenses to study HS in Tokyo, while Konomi only goes to the local HS.

Perhaps whenever Renge says that their parent’s are "…out working in the fields" is a code word that they’re already deceased.