hi mark.. its very sweet of you to show concern for your wife.. i would suggest do not make her do much activity or excessive exercise for the 1st 3 days of her periods as she is already weak that time. instead just take her for some drive or a good movie to pep her up. as far as food is concerned during this time women are weak as they lose lot of blood, so give her fruits like watermelon, papaya, oranges etc.. dates, walnuts, almonds as they are rich in good fats.. she needs to eat small meals every 2-3 hours.. to feel energetic.. give her juices, soups, salads like beet root-carrot salad..oats porridge for breakfast, sprouts/ egg whites as evening snacks.. you can also give her garden cress seeds with milk as they are super rich in iron.. make sure she drinks plenty of water..take care