Right now your mother is showing a normal sinus rythym on her ECG. That is a good sign.
There is some enlargement by her left atrium, usually due to high blood pressure, stress, lung disease or even obesity.
The right bundle blanch block, this affects the electrical activity in the heart, could be due to an infection, a heart attack, high blood pressure, it could be congenital, it could also be due to a pulmonary clot (embolism).
Inferior infarct, there are indications that there has been some cardiac tissue damaged.
T wave abnormality, could indicate blood flow problems in the heart.
More testing is required, probably a cardiac catheterization will be done. This is where a dye is injected into the heart to check blood flow. An ultrasound may be used to watch the action of the mitral valves.
Surgery may or may not be done, possibly a coronary bypass or stent would be placed. It depends on what her current symptoms are, the severity of the condition, and her current health. Medications may also be used, again, depending upon the findings.
I know I've given you a lot of "could be's." The ECG is only one test, I would expect more.
Ask her doctor.
Hope it helps.