It sounds as if she might have an infection in her eye or conjunctivitis or it might just be a little irritated. If she's keeping the eye closed or squinting with it, then she may have a scratch or injury to her cornea but regardless, the following is what I'd suggest:
1. You can apply a warm wash cloth or warm (not hot) tea bag to the eye/area for about 5-10 minutes which may provide relief. This can be repeated 2-3 times a day if you'd like.
2. You can gently rinse the eye with over the counter saline solution which should be available at most human pharmacies. You don't want to use the contact lens solution, though.
3. There are a number of acceptable human, otc ophthalmic preparations which will be acceptable to use; however, none will contain antibiotics since these would have to be prescribed by a vet.
The Systane products which are listed can be used in dogs, but the ones with vasoconstrictors, such as naphazoline should be avoided. These products are labeled as "taking the red out" or for "red eye".
Tears Naturale Nighttime
Systane Ultralubricant sterile eye drops
Advanced Eye Relief Nighttime
Akwa Tears ointment
I recommend treating 3 times a day
If the eye looks worse in any way or there's no improvement within a few days, then a vet visit may be wise.
I hope this helps, Deb