I think she is having chronic pancreatitis as i can guess from your description.
This is a condition in which pancreas gets inflammation that runs over longer time and leads to recurrent pains whenever someone tries to eat. This pain is in mid abdomen below ribs and goes to the back.
Fear of getting pain with eating and digestive problems because of pancreatic malfunction lead patient to avoid food and they keep losing weight that way.
Alcohol is a biggest risk factor apart from several other causes like gall stones, trauma ,steroids, mumps,autoimmune disease,scorpion venom,hyperlipidemia, ERCP, drugs etc can cause such problem.
when it is because of hyperlipidemia it also involves liver called steatotic hepatitis and pancreatitis.
Wahtever is the cause, I hope she will be getting best treatment for it and I wish her best wishes for her health.
Please feel free to post follow up questions.