Where is the pain located? Is it truly stomach, or located elsewhere? Is there any history in your family of GI issues, or food intolerance issues? Has she had any changes in her bowel habits? Have you kept a food diary to see if you can isolate any foods that seem correlated with pain production?
Thank you for your comment. I agree, I think her pediatrician should be doing more to look into this matter. That is why I am writing here, is because I feel I am not getting any answers from him.
Find a new pediatrician. That's not an appropriate answer for any doctor to be giving.
It could be a hernia or her gallbladder or any number of things, but a better doc would be looking into it.