Hi. 7 years old child and has pain in abdomen for 2 weeks- The probable diagnosis is a lymph node mass / worms/ enteritis / typhoid to name a few. Since ultrasonography is normal , I suppose there are no lymph nodes. Other probable reason are worms- give a dose of dewormin. I hope she has reveived a course of an antibiotic and metronidazole. Go for stool test for three consecutive days - gives a great information sometimes. You can gice he meftal spas- for 5 days. But again to tress the importance of a proper diagnosis. If necessary you can go for another opinion or see a Pediatric Surgeon .