Normally dogs open their eyes between 10 and 14 days so age shouldn't be an issue.
When puppies first open their eyes there may be a small amount of discharge. This is normal and should clear up within a few days. However if the discharge is green, it could be a sign of infection.
If your puppy's discharge is green, you should take her to the vet as soon as possible. Infection can spread very quickly in puppies, causing blindness or other problems.
The vet will prescribe medication to treat the infection and may also recommend flushing the puppy's eyes with saline solution.