Auscultating Fiancé

So I think my fiancé has pneumonia, what will I hear when I steth her chest tomorrow night?

You will hear crackles , try this site http://www.easyauscultation.com/crackles-lung-sounds.aspx

So when I steth her should she be undressed from the waist up?

So I think my fiancé has pneumonia, what will I hear when I steth her chest tomorrow night?

I think she should be seen by an actual medical professional!

Agreed, she needs to be stethed by a doctor who will also do a chest x-ray, but if she does not want to go to the doctor, and if he listens to her lungs, tells her how bad her lungs sound and lets her hear for herself, it may help persuade her to go to the doctor. Then, as she is getting better, he can listen to her and reassure her.