How to keep cat's eye ointment in? When to seek vet treatment?

Species: Cat

Age: 1

Sex/Neuter status: Female, neutered

Breed: American Shorthair

Body weight: 7lbs

History: URI in February, generally healthy

Clinical signs: yellow and green discharge from both eyes. Swollen left eye and redness around eyelids

Duration: 72 hours

Location: Washington DC

I adopted two one-year old cats siblings from a local cat cafe this past week. One kitty (the boy) arrived with sneezing, which has thankfully gone away. The girl has had discharge from her eyes the past few days (yellow and green) which I have been wiping away with a clean, warm, paper towel.

I called the cat cafe today regarding this who gave me an extra tube of Erthromycin Ophthalmic Ointment to put in her eyes twice a day for five days. I just gave her her first treatment but noticed that she started wiping her face and her eyes a few minutes after I put the ointment in. My question is, how concerned should I be about this? Should I try to prevent her from wiping her eyes after? When she does this, should I try and put more in?

After how many days of treatment (if I don't see signs of improvement) should I take her to a vet?

Anything else I should be considering to make this treatment effective?