Help with my mom!!!!!!!?

ok im 12 years( turning 13 in 2 weeks) and ever since i remember my mom has been having these cramps. Now my mother is slightly older than most mothers (she 50 & goin thru menopause). My grandparents died so its just me and her.When she gets the cramps they are really bad and she gets them in her thigh or claves or her feet. Did i mention shes is slighty on the bigger side in terms of weight. and when she gets them i just rub it with sports balm / icy hot yeah that kind of stuff. she never ever wears heels.......she cant wear shoes that are too hard...and when she gets it i just take off her pants and rub. But i need answers because i hate seeing her in pain. What causes them? how can they be prevented?Help!!!!!!!!!!!!!!!!!!!!