Others may also missed the part where op said they both work full time, have a house to run , and there's 2 sets if elderly parents to look after. Of course everything is military style. Because how else can it be when you are that busy.
Lots of women hold down full time jobs and take care of households. Some are single parents. I have five DCs myself, and have done the two parent and single parent household routines, the latter while working full time.
It doesn't have to be a case of military precision, and with so much on the OP's plate, the idea of cooking every evening of the week is ludicrous.
Identify 6 or 7 meals that are really easy to make and use ingredients that are easy to come by and buy in bulk once a month - cans of tomatoes, frozen spinach, cream, garlic, frozen veg, rice, pasta, couscous, chicken stock, beef stock, a variety of lean meats, canned beans of various kinds, fish, seasonings that go with a lot of dishes. Make a big pot of something easy twice a week and eat it every evening until it's gone. Rotate the recipes every three weeks or so. Job done.