My Mother Is 96 Years Old. When She Sits Down

My mother is 96 years old. When she sits down to eat, she often looks at the food and say that she can't eat it after all.
Three weeks ago she had a fall fracturing several ribs and was treated with an antibiotic for border line pneumonia. About two days ago she began experiencing dry heaves. As a result she feels nauseated and won't eat. What could be the cause? I'm wondering about a hernia