Hi.
You are correct that pneumonia generally presents with cough and fever. However, for geriatric patients - the presentation may only be poor appetite, fatigue, and a cold. It is good that she seems to have recovered. I am not surprised that a CT scan was requested after the chest X-ray - again, age may make some findings difficult to discriminate in an X-ray due to the contributions of age.
I'm glad she has recovered.
I'm not sure how accurate was your weight loss documentation - I am assuming that it may have been overestimated. Discuss this with your doctor, and inquire about other tests to evaluate the weight loss.
Stay positive.
What happened with the pulmonary tests? 18 lbs is a lot to lose in a week. fever is usual with pneumonia as well as yucky stuff you cough up