Mom has back pain around the shoulder blade area, right side of the body.she said it hurts especially when she's taking a breath.what could cause this?

Multiple causes: C6-7 disc herniations can cause "sharp subscapular pain" with numbness down the arm to the middle finger. A more common cause of pain with breathing can also be pneumonia. Compression fractures of the thoracic spine can cause a combination of back pain with radiating pain upon deep breathing. History is very important to help understand the condition a bit more.

Depends: Peri scapular pain can be from either cervical or shoulder problems. But if pain is exacerbated by deep breath then either inflammation of lining of lungs ( pluritis) or inflammation of rib joint can be the cause. Nsaids may be first thing to try.