My 11 1/2 Year Old Granddaughter Had Pain In Her

My 11 1/2 year old Granddaughter had pain in her abdomen yesterday, along with sweating and paleness. it was short lived. She laid down for 5 minutes and it was gone. My question is, what precedes the onset of menstruation in young girls. Could this be a symptom of that? She has been looking pale lately and had one or two other stomach incidents.