Hi Welcome to HCM.
your mom is suffering from high BP
instantly nothing will happen.follow your doctor advice
she cant tolerate if BP comes down fast as body got adjusted to that high level BP.
reduce salt and oil intake.
investigate for blood sugar level,lipid profile
,renal function tests,regular eye examination etc.
do regular follow up to your doctor,stick to one doctor.
Hope I clarify your querrry.
Have a good health