She probably has some kind of disease/infection, whether you think she's sick or not.
Research those symptoms and find out what it is, maybe post in the Emergencies/Injuries/Diseases forum, to learn what kind of medication might cure it.
Here's search for watery bubbly eyes:
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The stress causes a disease to erupt/escalate.....
.....just stress alone doesn't cause watery bubbly eyes.
Age can be a stressor, aging immune systems sometimes don't function as well.