Well I am no doctor and I hopefully am wrong but.... My grandma had the same exact problems last year. It was dignosied as cancer. So they took her leg. And evre since then and before then she has had the cancer in her lungs and is now in her heart. But she was the same way. If she would have gone she might have had a better chance of beating it.
This woman needs to see a doctor. If she won't go, try telling her that the shortness of breath may be caused from pneumonia and she really needs to get a chest xray just to make sure. This is true (but unlikely), especially if she has Congestive Heart Failure. The chest xray will show congestive heart failure, enlarged heart, enlarged arteries related to heart problems, etc. If she is afraid to have the heart checked on it's own, she might go if she thinks it is pneumonia because she will know you can take meds and 'get over' that, while she is afraid of it being her heart, which might kill her. The radiologist always evaluates the heart on any chest xray, so she will also be getting her heart checked. Sneaky, but do-able. Good luck
Maybe congestive heart failure.