Restated #: lips look fine but she has the habit at 70 to press her top & lower lip together in a repetitive way. all exams are negative. heavy jowls?

Drug side effects: Certain drugs e.g. Reglan (metoclopramide) and anti psychotic drugs can produce tardive dyskinesia as a side effect. One of the features of tardive dyskinesia is repetitive abnormal motions with the lips and mouth.

Is it just a nervous: Habit, one of her characteristic expressions, or does it happen without her thinking about it/ controlling it? If it's the third one, i'd suggest a consult with a neurologist. It's not from the jowling.