Mr Ó Donnghaile resigned from the party last year after sending allegedly inappropriate messages to a teenager.
Announcing his resignation, Sinn Féin issued a statement in December 2023 where Ms McDonald praised Mr Ó Donnghaile for serving “diligently” and making a “valuable contribution” to the Oireachtas.
The statement also said the former senator was resigning on health grounds.
The boy has since said this statement, which he described as “glowing”, was like a “mental stab”.
Speaking at the launch of Sinn Féin’s healthcare policy, Ms McDonald said that she and the party were concerned for Mr Ó Donnghaile’s frame of mind at the time of the statement.
“I was concerned, we were concerned about his frame of mind and his safety, and therefore the logic of the manner of handling,” Ms McDonald said.
“But of course, with the benefit of hindsight, the statement shouldn’t have been made. And I say that because it caused hurt to the young person in question. That’s my concern,” the party leader added.
She also denied that the statement in December was a way for the party to leave the door open for the senator to return.
“When somebody breaches trust in the way that he did and acted inappropriately, although I have to emphasise not criminally inappropriately, there is no door back from that,” Ms McDonald said.
The Sinn Féin leader said the statement on the former senator’s resignation did not breach the trust of the public.
“I think in the circumstances, my concern is for the young person at the heart of this. And as I said earlier, I’ve written to that young person through their mother, that’s my primary concern, was any upset caused to them,” Ms McDonald said.
Ms McDonald issued a statement in the Dáil to correct the record that the boy who received the texts was in fact 16 and not 17 as previously stated. She also apologised in the Dáil for the hurt her statement caused the boy.
Ms McDonald said she deeply regretted the hurt she caused and that Mr Ó Donnghaile faced consequences for his actions.
“Niall faced consequences, his political career is over, his membership of Sinn Féin is over, and for someone like him, those are big sanctions,” Ms McDonald said.
Separately, on the resignation of former Sinn Féin TD Brian Stanley, Ms McDonald said the party did everything they were obliged to do in handling the complaint.
As reported in the Sunday Independent, the woman who made the complaints against Brian Stanley believed Sinn Féin was “protecting the party” in their handling of the situation. However, Ms McDonald said the party did their “duty”.
“We did it in a thoughtful, in a methodical and in a fair way, and in a way that respected people’s privacy, as well as everything else. So yes, we have done our duty,” Ms McDonald said.
She added that Mr Stanley’s behaviour was not something that Ms McDonald or the party would take responsibility for.
“Brian Stanley’s bad behaviour is a matter for him. I’m not responsible for that. I will not take responsibility for that,” Ms McDonald said.
“I am responsible for, as the leader of the party, the investigation and inquiry into a complaint such as that when it’s made, and it was done by the book,” she added.
Sinn Féin are yet to select a candidate to run in place of Brian Stanley in the upcoming general election in the Laois constituency.
Ms McDonald said they will run a candidate in the county, to hold on to what she said was a “Sinn Féin seat”.
“For our part, now we will move to select an alternative candidate for Laois, and we will go in there to mount a very strong campaign to hold what is a Sinn Féin seat,” Ms McDonald said.
The leader confirmed that the party currently has 60 candidates selected across the country to run, but that this will increase to 70 for the election.
The number is significantly higher than the 2020 election, when the party ran 42 candidates, 37 of whom were elected.
“We will run sufficient candidates to give people a real choice, because that’s what it will come down to for an alternative government, either more of the same with Fine Gael and Fianna Fáil or chance and an opportunity for a new government,” Ms McDonald said.