As you didnt mention the age/weight/built of your mother . but as much i can understand your mother may have high blood pressure
at present. swelling of legs indicating the poor pumping out blood by the heart that may be due to Left ventricular failure & there may be associated with portal hypertention . it is very critical condition . you should go for Echcardiography and if it is possible you should hospitalized your mother for better care and further investigation and evaluation.
hope for better health of your mother