Why isn't she seeing a doctor? This sounds serious. It could even be appendicitis, which may become a life-threatening emergency.
http://en.wikipedia.org/wiki/Appendicitis
http://www.mayoclinic.com/health/appendicitis/ds00274
Or it could be one of these:
(Taken from
http://www.mayoclinic.com/health/abdominal-pain/MY00390/D...
)
Causes of lower right abdominal pain include:
* Aortic aneurysm
* Appendicitis
* Cancer
* Cholecystitis (gallbladder inflammation)
* Diverticulitis
* Ectopic pregnancy
* Endometriosis
* Inguinal hernia
* Injury
* Intestinal obstruction
* Kidney infection
* Kidney stones
* Mittelschmerz (pain associated with ovulation)
* Ovarian cysts
* Salpingitis (inflammation of the fallopian tubes)
* Seminal vesiculitis (inflammation of the seminal vesicles)
* Tuboovarian abscess (pus-filled pocket involving a fallopian tube and an ovary)
* Viral gastroenteritis (stomach flu) (stomach inflammation)
I would have her see a doctor right away... Better be safe than sorry.