Your snake probably has one or more retained eyecaps on that eye. If enough layers are built up, the eye may never clear, but if it's just a few you may be able to help. Try using a cotton swab dipped in clean water and gently rubbing the eye and area around it every day until it releases or she sheds again. That may not work, and if it doesn't a good reptile vet can help you take further steps to fix it. Do NOT tug on any edges you can see as you could permanently blind your snake in that eye.