Hi welcome- how old are your sister?? Normally quickly eating or bug stuff or improper chewing may happen. Th Is can be also seen due to liver diseases.

Hello there...i understand your concern...try eating several small meals instead of three large ones whenever you can...Avoid foods that irritate your stomach, especially those that are spicy, acidic, fried or fatty... avoid coffee,tea etc... Avoid stress,consider calming activities, such as meditation, yoga etc...sleep with head raised position and have dinner at least 2 hours before sleep...get an ECG done and Consult nearest physician they will do the needful.