DD is 13 and started her periods 3 years ago. They're quite painful and she is prone to fainting on day one. She's fainted at school, at home and - memorably - at Disneyland during her very first period.
Today is day 1 and instead of fainting, she's been quite sick, writhing in pain and very unhappy. I phoned 111 who were actually brilliant. A very lovely female GP went through lots of things and DD is calmer and has finally kept down ibuprofen and paracetamol. The two together seem to have taken the edge off. The GP says that we might want to explore mefanemic acid but I know this has its downsides. She also agreed that birth control at 13 when it's only very bad for 1 day out of 33ish, is probably not advisable just yet but can be revisited down the line.
I'm fortunate in that some painkillers, exercise, and a hot water bottle manages any pain I experience. DD is a stoic, capable young woman and it's clear that she's really suffering so all and any advice would be happily received.