But my pads and tampons and lots of Midol/Ibuprofen or other pain medication. Have sweets like chocolate or ice cream around and heating pads for cramps. Also make sure they drink lots of fluids because some girls get really sick on theirs or feel so sick they don't eat or drink. I feel for you OP! Just hang in there!

If the girls don't know what's going on, you could start by giving them some female products that your wife, presumably, keeps around. From there, explain to them what they are experiencing. Try to keep an eye on their symptoms and monitor their pain and cramping, major depression or irritability, and try to get a vague idea of how heavy their flows are. The first two can be symptoms of rather severe disorders, the third can cause anemia. Also inform them of the symptoms of a yeast infection, because they may be more liable to them during and just after their menstruation. Also inform them about toxic shock syndrome, which occurs most often from tampons, but can also occur from pads. They may experience fatigue and brain fog as an effect- if so, caffeine may give some relief. If any of them are having serious issues with pain, fatigue, bleeding, focus etc., you may need to take them to a gyn down the road. You'll probably need to get more sanitary products- get a few different kinds, if possible, and avoid scented- and make sure they change their pads at least every six hours, though four or three would be better. Chocolate does help some people- dark is better for the medicinal aspect, but milk chocolate may be preferable for the comfort food aspect. Bananas and other potassium rich foods can help reduce cramping. Make sure they drink a lot of water, too- some people get dehydrated during their period. Dramamine or something similar can help if any of them experience nausea as a trait of their cycle. Outside of that, get them a few things that they crave- but don't over do it. Midol and other minor pain killers can help. For a heating pad, long grain rice that is completely uncooked and dry (the cheap kind, basically) put into a tube sock can be put into a microwave and heated for a very long lasting heat pad. It smells a little funky; and going more two or three minutes at a time in the microwave isn't the best idea. The first can negated with essential oils according to some people, and the fire hazard can be reduced by teaching the girls to be careful.