Privilege means never having to say you're sorry
So is Mary Lou McDonald really in trouble, or is it all a storm in a parliamentary teacup? There's no doubt that, like all TDs, she could not be sued in court for anything she says in the Dail.
Article 15.12 of the Constitution says: "Utterances made in either House wherever published shall be privileged". That means that, even if the statements are untrue and defamatory, the subject(s) of those statements cannot sue in the civil courts.
That constitutional provision allows TDs (and Senators) to name individuals without risking the financial and reputational cost of a successful defamation action by an aggrieved individual.