This is isolated systolic hypertension
, quite common in elderly. The higher value is called systolic pressure and occurs when the heart contracts and the lower value is called diastolic pressure and occurs when the heart relaxes. The difference is known as pulse pressure. As you mentioned, the usual pulse pressure is around, when the BP is typically 120/80. Wide pulse pressure and high systolic pressure is common in elderly and is due to the stiffness
of the arteries (blood vessel carrying oxygenated blood). Since she was shaking, that means she was feeling cold
or excited. This will stimulate the sympathetic nervous system
and cause elevation of systolic pressure. Most probably it will come down when you check it after she has settled down. There is also a waking up surge in sympathetic activity, which can raise the systolic pressure. Rarely diseases like a leaky aortic valve
can also cause a wide pulse pressure.