It happened with my kitty too. The vet told me to clean the eyes with cotton soaked with warm water every now and then. He is looking better now.
My Kittens' Eyes Keep Getting Sealed Shut And There's A Yellow Discharge? What Does It Mean And How Do I Find The Right Medicine?
Sounds like it is an eye infection. I would clean her eye tonight and get her into the vet tomorrow.
Take the kitten to the vets it happend my cat the gave me eye drops for myn