If I were you, I will record the video that I noticed the maid that I had provided meals for her (record the stock too), make sure she understand she could not claim anything if she prefer meals from other people/herself.
By the way, there are no free meals, I don't think other maids will take care of her dinner, but of course she has to pay the same value for exchange....if she got food poisoning, you will be the one who pay for her doctor visit.