The good news is that almost anything you do to improve her diet, lifestyle or general health will impact favourably on your daughter's PMS.
A small reduction in your intake of caffeine and/or refined sugar, a little more exercise, a little more sleep – all of these will help.
If you move your daughter towards a healthier diet containing more fruit and vegetables and fewer highly processed or ‘fast’ foods, you are likely to notice improvements before too long - I appreciate that this may be hard with a teenager!
Many women find that improving their bowel function reduces many of the physical PMS symptoms such as bloating and cramping pain. Molkosan® can be very helpful with this.
Stress is a big factor in many health issues, as it uses up valuable nutrients. It is, therefore, worth looking at a good Vitamin B support and Magnesium, to keep your daughter calmer.
I hope that this helps. Please come back to me should you require any further information and do let me know how you get on.