Runny Eyes in Cats - Possible Causes:

VERY runny eyes without conjunctivitis (no redness)

It's conceivable that her tear ducts are blocked which merits no treatment.
Allergies manifesting in the eyes also look like this, and merits no treatment unless there's redness.

Sinus inflammation can appear in the eyes - even though it's BEHIND the eyes. It's associated with a TON of sneezing and can be treated AND diagnosed with a short course of anti-inflammatories.
Nasal polyps can look like this as well, same test/treatment: Response to prednisolone. There is an amazing and invasive surgery for nasal polyps which I don't really recommend.

Sinus infections cause depression and fever and loss of appetite as well as runny RED eyes.

Viral upper respiratories can cause excess tearing as well, but there's no 'decent' treatment besides expensive anti-virals, steroids of 'some value' and maybe lyseine - except that the CAT doesn't care about runny eyes enough to have to take pills and eye ointments.

PLAN: Best one is watch for: Waning appetite, redness in the eyes, sneezing on the uptick, depression, nasal discharge going to colored or thick, open mouth breathing, crusting of nose. These can be SERIOUS if fever crushes the appetite or the impact on the nose compromises 'smell' and they go off feed because of that. A humidifer helps a LOT.

There are DIAGNOSTICS for cases like these and they run into the thousands of dollars in corporate climates with neuro exams and urinalyses tacked on.

If it were me: I'd use Cypraheptidine on the 'wettest-face' days and see if it helps. Try a steroid if it lasts more than 10-14 days. More aggressive therapy if you see any of the hallmarks I listed above.