Thanks for writing your query.
After reading your post, I would like to suggest following investigations for your friend :-
1. Complete Blood Count(CBC).
2. Stool examination.
It might be a possibility that she might be having infection of the gastrointestinal tract.
She can be give antacid
40 mg along with Domperidone
10 mg once a day before meals along with antibiotic like Ciprofloxacin
500 mg twice a day and antiamoebic like Metronidazole
400 mg thrice a day.
She should have light meals without spice and prepared under hygienic conditions.
She should drink lots of water to maintain hydration.
If the problem persists, get her examined clinically.
I hope this is helpful to you.