My 6 y/o has been complaining for the last 6 months Tummy ache/pain of the abdomen (around the navel area)/slightly swollen abdomen/discomfort when eating (will only eat a few bites)?

Hi.
My question is for my child:
Age: 6
Sex: F
History: No previous conditions or hospitalization
Meds: None
Symptoms: Tummy ache/pain of the abdomen (around the navel area)/slightly swollen abdomen/discomfort when eating (will only eat a few bites)/lasts about 15-60 minutes at times, sometimes longer
It usually starts in the mornings, but limited to that time. After a lay down/nap & a cup of black tea seems to relieve it to an extent. She has been complaining for the last 6 months with the pains which started off once or twice every few weeks, but has increased to a few times a week in the last 3 weeks. Once the pain is gone, she instantly runs out of bed & out side to play, which she loves to do. Her diet varies, so i can not make a connection to food, aside from a daily intake of Weetbix/Kornflakes/Fresh milk/Bananas/Tea, those are the only daily foods, which she has always eaten/drank.