That’s such a nice gesture!
Girls can have Pre-menstrual Symptoms(PMS) that can cause body aches/ cramps, mood swings and many other symptoms. So there are a few things that you could do to help;
• Make her feel comfortable by not planning anything strenuous for those days. Cuddle a lot and cook meals for her to make her happy.
• If she has mood swings, do not react harshly. Be calm and understand the situation.
• Support her and surprise her with a gift or even chocolates would do the trick.
All the best.