ok several things spring to mind;
dead central pain does NOT sound like gallstones. it tends to be more over to the side and the pain radiates through to your back. It is EXCRUCIATING. You feel feel very restless too-lots of shifting about.
dead central pain DOES sound like hiatus hernia which can feel like a heart attack, it's so painful.
if it IS gallstones then the best thing to help stop attacks occurring is to follow a very low fat diet. Nothing you eat should contain more than 3g of fat per 100g. So lean chicken breast, rice, vegetables basically. It REALLY helps and has the added bonus of helping a bit of weight drop off. i lost 2 stone due to this diet.
If it is haitus herni athen avoiding Citrus foods, such as oranges, grapefruits, and lemons, and orange juice, grapefruit juice, cranberry juice, and lemonade
Chocolate
Fatty and fried foods, such as fried chicken and fatty cuts of meat
Garlic and onions
Spicy food
Peppermint and spearmint
Tomato-based foods such as spaghetti sauce, pizza, chili, salsa, and tomato juice
Coffee, tea (including decaffeinated versions), and alcohol
Carbonated beverages
Dairy products, such as whole milk, ice cream, and creamed food will help.
my other [probably less helpful] thought is that you seem very passive. Sometimes our kids and teenagers-especially teenagers-make really poor decisions and choices and there does come a time when we have to step in and say 'i can't allow to make that choice anymore'
i have an almost 16 year old. If he was screaming in pain then i would either bundle him into the car and take him to see a medical professional or call an ambulance and have him taken that way.
If it is a gallbladder problem then one day a stonemay get caught in the bile duct and she could die! It's serios thing!
Plus if she is not menstruating properly then that too really needs looking at. I really think you need to be stronger and more active than you are being.