Can you tell me what it means for me if our bankruptcy is discharged but not closed.
The trustee will not close it until she receives our 2008 tax returns. Can the bankruptcy
Discharge be reversed or dismissed after the discharge date if she is not satisfied with our tax returns?

Yes.

It is up to the Trustee to make the final decision on closing the bankruptcy.

If the Trustee finds anything out of order, they can make adjustments to the bankruptcy and the closing of it.

Yes, until it is closed the trustee has options to reopen the case.