I grew up with three sisters. My poor dad would say he got PMS 5 times per month!
My niece has TERRIBLE pms.... last easter she was on my sister's couch. This girl is a straight A student and to that point (things have changed a little now, lol) had not done a bad thing ever. She was moping the whole day. I sat by her and she starts to bawl... no one cares about me (the first born grandchild/niece etc.. A GIRL, My God-daughter, we dote on her... blah) and my mom doesn't even ask if I do my homework.... wah wah wah.. OMGosh... I almost laughed... but I controlled myself. I saw my sister and asked what was up.. she said she WILL get her period tomorrow.. OMGosh.... that poor kid, honestly I saw her three days later and she was perfectly normal again. She now takes birth control and it goes much better for her.
I wish your lovely daughter an easy time of it.... I am actually thrilled to be at the end of it all!