Prosecutors say Kathy Boumpani entered the plea Thursday and will remain free pending her scheduled March 18 sentencing. Her husband Louis Boumpani remains jailed on the charge.
Federal authorities say they tried to bring knives and shotgun shells through the building's metal detector.
Officials say they wanted to talk to the FBI about mortgage fraud. Kathy Boumpani told a magistrate their house had been foreclosed on.
Her potential sentence ranges from probation to two years in custody.