Can you tell if the fluid is clear or cloudy? It helps if you sort of push upwards on the underneath the eye one the nose side as you might be able to see the fluid collect. If its clear then she probably just got something in her eye. If its cloudy then she's potentially got an infection. If its the latter then you might want to take her to the vets.
In the meantime boil some water, put salt in it (half a teaspoon in a pudding bowl of water), wait for it to cool and bathe her eye with some cotton wool. This will help her whatever is wrong with it.
Fingers crossed she's OK, and its just a bit of something in her eye.