I'm using the legal definition of it.
(4) The term "covert agent" means
(A) a present or retired officer or employee of an intelligence agency or a present or retired member of the Armed Forces assigned to duty with an intelligence agency
(i) whose identity as such an officer, employee, or member is classified information, and
(ii) who is serving outside the United States or has within the last five years served outside the United States; or
(B) a United States citizen whose intelligence relationship to the United States is classified information, and
(i) who resides and acts outside the United States as an agent of, or informant or source of operational assistance to, an intelligence agency, or
(ii) who is at the time of the disclosure acting as an agent of, or informant to, the foreign counterintelligence or foreign counterterrorism components of the Federal Bureau of Investigation; or
(C) an individual, other than a United States citizen, whose past or present intelligence relationship to the United States is classified information and who is a present or former agent of, or a present or former informant or source of operational assistance to, an intelligence agency.
Only then would this have been a voolation of Section 421 ( Protection of identities of certain United States undercover intelligence officers, agents, informants, and sources )
That lays out what specifically they mean when they refer to "covert agent" in the statute.
And the reason for that is so that it doesn't encompass all covert employees. They wanted it to specifically apply to employees who worked overseas because revelation of their identities could endanger operations and all those involved.
They didn't want it to apply to covert employees here because it had the potential to go beyond the intent of the act--to protect overseas operations and sources.
Those criteria are important for determining if a law was broken. But if she didn't meet that criteria, it doesn't mean she wasn't covert or undercover. It just means the act doesn't apply to this situation.