If she has green/yellow discharge, she has an infection and needs antibiotics. Once it reaches this point, you need to see the vet with her for antibiotics and an exam. I would also suggest a fecal exam because parasites can sometimes caus eye discharge.
So - step 1 - see the vet today for an exam. Until you can get there, you can flush the eyes with warm saline and remove the gunk. Then blot the eyes with a clean, dry cloth.
Let me know if you still have questions.