I have part time to do the buying and cooking and she will tell me the amount spent for each meal every day. on average, about 40 dollars for two disc and one soup (not boiled one), enough portion to serve three adults (including my maid) and two children for dinner; and reserve part for my girl and my maid for lunch the following day. Sometimes, if there are too much food, I will even pack lunch for school.
No problem and so far the 'quality' of food is good.
Your calculations are for 1 meal for entire family (dinner) + lunch for 2 to 3 per day ==>good food.
This maid has to buy 3 meals for whole family per day.
Either the maid has to go on diet and skip 1 or 2 meals a day, or she has to buy the $2/batch type of vegi.+ not enough meat for the whole family+ dead fish for $5/plate, or buy 走私肉。
The employer is doing themselves more harm than good.
If $40 is only for dinner, that will be ok. If $40 is not only for dinner, but also for breakfast and lunch, then...I think that's a bit too difficult to do it.