You need to take her to her pediatrician to discuss this. She may have PMDD, which is more severe than PMS. It includes emotional symptoms as well as alot of gastrointestinal problems, and sometimes acne. It is caused by the body's reaction to the change of hormones present in the menstrual cycle. I noticed all of the above in my DD related to her cycle, as well as a very irregular cycle. I started giving her a regular vitamin supplement about a year ago, noticed no difference.
Her pediatrician diagnosed PMDD, and prescribed Yaz, which is generally used for birth control burt has been shown to be effective for treatment of PMDD . She has been on it about 5 months and has had about a 75 to 80% improvement in her symptoms, except for the acne which is nearly all gone. I was not thrilled with the idea of a daily med for my DD, but I believe this is the proper treatment for her at this time.
Good luck to you- I know this issue can be very frustrating for all of you.