Week day - she will eat some stock at home, such as noodle, can, ham or bread as she need stay home to look after baby.
Weekend - if nobody home she will go to the market to buy some vegetable, meat..etc for the coming week and then she can buy lunch box for reimbursement, so far she will not claim more than $25 average is $15 (she is quite reasonable and she know my family is not so rich!)