I am also a full time mom.
I try to ask my bun bun to cook (follow my instructions of course). If she has no talent in cooking I will cook but will only cook for my family! I won't cook for her as in my opinion, I am the boss I won't cook for her!
So most of the time I just buy her a collection of food enough for a week (chicken wings, pork chops, pork ribs, fish) and I ask her to cook it herself. I don't care what she cooks and she is quite happy with that arrangement. Sometimes if she likes some particular thing (that I think is acceptable), e.g. eggs, I will buy for her.
1 meal she will cook like
4 chicken wings or 1 pork chop or 5 pork ribs or 2-3 fish (depending on how big the fish is)
so I think that amount of food is ok.
For lunch, I usually eat bread myself. And I ask her to cook for my son. She will cook noodles + vegi for herself and eat some bread as well. I don't care. I buy her 2 loaf of bread for 1 week, she eats the bread for lunch and breakfast.
for the vegetable, I ask her to cook (usually just boil) and I will give her some in her plate, usually she will tell me 'that's enough'. She only needs a little bit...not even 1/4 of the dish...I think they like to eat more meat / fish than vegetables! Sometimes when we are not at home, I just give her 1 tomato, green pepper or some celery to cook with her meat. But I find that she doesn't cook them but just leave them in the fridge!!! I don't care if she touch it or not as I have given her the food!!! she can't tell me that I am stingy!!! haha
These people who are not Chinese may not like your food and your cooking style. So I think to save my time and my 'air', I won't cook for them and just let them cook themselves.