I can't really tell for sure, but in the picture of your gorgeous girly with the carrot, it looks like it could be a hay poke injury/ulcer forming in the centre of her eye? The darker pink area?
If you could get a vets appointment ASAP tomorrow the vet will be able to tell if it's normal or if she has an injury - they usually put an orange/yellow dye in the eye to find out.
Time is of the essence with eyes, they can quickly get other health complications if left untreated, but often heal quickly & fully if treatment starts promptly.
If she'll let you & it doesn't stress her, try having a look at her eye close up & see if you can see a foreign body or debris in the eye.
Just dripping a few drops of boiled then cooled water into the eye from above (with a twisted, paper kitchen towel wick) might be enough to soothe the eye overnight and keep it hydrated-until you can get to the vets tomorrow.
Eyes are generally the same no matter what species of animal, so if you don't have an exotic vets nearby, a general vets will do
You'll probably be prescribed antibiotic eye drops, often Isathal or Tiacil for her & hopefully some oral painkillers (usually metacam/Loxicom) just to keep her comfortable if it is an injury.
I keep a tube of Remend
Remend Corneal Repair Gel - 3ml
In my fridge as a first aid basic for the usual Friday night/Bank Holiday hay poke incidents. Until I can get to a vets.
The eye licking is also a bonding /accepting & cleaning/grooming behaviour.
I wouldn't suggest using the eye drops you have as Polly may be ingesting them when she's grooming her new companion & Ive not heard of them being used on piggies before, so best check with the vet first
Often guineas are quarantined so they don't pass any illnesses to each other, but if Polly was lonely then a reputable rescue or vet will sometimes suggest no quarantining necessary for the social welfare of your original lonely/bereaved guinea.
Good luck and let us know how she gets on
... Oh & more pics please of both piggies, we love piggy pics
Xx