My 13 Year Old Daughter Ate Supper About 45 Minutes

My 13 year old daughter ate supper about 45 minutes ago. About 30 minutes after she ate she started having pain on the left side of her abdomen beneath her lung and diaphragm. She had one cup of mildly spicy pizza casserole, a bread stick, a serving of corn and a glass of milk to eat. The pain is worse when she takes a deep breath and if she tries to change positions, it makes the pain worse. She describes it as a constant achy pain with sharp pains that come and go. She had a bowel movement before supper and isn't exhibiting any other signs of illness. What should I do for her?