7 Year Old With Frequent Headache And Stomach Ache. Had Strep Throat. Should I Be Concerned?

My 7 year old daughter complains daily of headaches , stomach aches and sometimes of being tired for going on 2 months. She participates readily in gymnastics, goes to school, plays with friends and siblings. She does not take any medications regularly (although did recently take antibiotic for strep throat ). Finished about 2 weeks ago. She has a history of headaches which make her tired; she will vomit and sleep and be fine when she wakes up. These headaches have happened only a handful of times and typically when there is some big change in routine. Her teacher has been contacting me almost daily to say that she is very concerned about my daughter, who has been complaining constantly and making frequent trips to the school nurse. Any suggestions? I will be making an apt. with our GP, but would like to go in with an idea of what course of action should be taken.