I hate what Lerner is doing, but this whole “you waived your 5th Amendment rights” business is B.S. You should never be compelled to incriminate yourself, no matter what you’ve said up to that point.
As an employee of the US Gov’t and a person with access to various persons(and Orgs.) personal information, she should be charged with the various crimes and let the records convict her. She wouldn’t have to speak to anyone. However, withholding these records from Congress and other prosecutors should be more charges themselves.