Verification of the original copies of the certificates is the part of the recruitment process. Job candidate is expected to be in possession of the original copies. However, by chance if he/she does not have these, then leeway can be given and some extension can be given to get the certificate from the outstation. However, this should happen before the candidate join the company.
In the case at hand, you have given sufficient time to produce the academic certificates. Since she has not done that, you may issue her show cause notice as to why disciplinary action should not be initiated against on her failure. You may put her under suspension till she acquires the certificate. If she fails to produce the certificate, then terminate her services.
30th March 2018 From India, Bangalore