Do you smoke?
Apart from diabetes do you have any significant past medical (especially heart disease) or surgical history?
Do you have pain on pressing (tenderness) the area of pain?
Are you smoker?
Holding your daughter increasing pain, points to the musculoskeletal origin. A possibility to consider is costochondritis. It is inflammation at the junctions of rib and cartilage or with the breast bone. Multiple ribs can get involved. Anti-inflammatory analgesics (Ibuprofen), local analgesic ointment or spray and warm compresses are helpful in this. A chest brace in your case would be helpful. Read about the costochondritis, in this resource;
With your history of smoking and having atherosclerosis; will need an EKG and chest x-ray, as in any chest pain we need high index of suspicion to rule out lung and heart disease.
Your follow up questions are welcome.
Happy New year.