mainly your daughter is having gastritis
after eating meals are common symptoms of gastritis - caused by irregularity in eating meals, consuming improperly cooked food, excessive eating of oily foods, overeating and drinking strong coffee or tea.
There is one more reason is there (which may be applicable for your daughter's age) that is a natural phenomenon in the body. That is the part of the body which is more active gets more blood supply. So while eating and digestion your stomach and intestine gets more blood supply. Comparatively other area get lesser blood supply. This is called POST PRANDIAL HYPOTENSION
, But this is more common in older individuals.
Avoid gastritis by avoiding the food as mentioned earlier - maintain a periodical bland diet till she gets alright to alleviate symptoms as soon as possible