Kate McCann admitted today that listening to claims that she faked her daughter Madeleine's abduction was difficult - but said nothing could be as bad as losing her child.
She and her husband Gerry have sat through two days of court hearings in which former Portuguese detective Goncalo Amaral has called witnesses to support his allegation that the little girl died in her family's holiday flat.
Mrs McCann insisted that the couple were right to take legal action against Mr Amaral and said she was confident they would win.
Speaking as she arrived for a third day of hearings at the main civil court in Lisbon, she acknowledged that this week had taken its toll.
"If I'm honest, our daughter's been taken and nothing's ever going to be as bad as that," she said.
"It's still been difficult, it's been emotive, because I know what's in the case files, I know what the conclusions are.
"So it's difficult to hear something that's incorrect and inaccurate.
"At the bottom of all this is a little girl, and I think it's important that we don't forget that."
Mr McCann flew back to Britain last night to return to work and his wife was accompanied to court today by Fiona Payne, one of the friends on holiday with the couple when Madeleine disappeared.
Mr Amaral was the first head of the Portuguese police investigation into Madeleine's disappearance from Praia da Luz in the Algarve on May 3 2007.
He has called a series of top Portuguese law enforcement officials as witnesses in his attempt to overturn the McCanns' injunction on his book about the case, Maddie: The Truth Of The Lie.
Chief Inspector Tavares de Almeida told the court on Tuesday he believed that Madeleine died in her family's holiday apartment and her parents covered up the death by inventing a kidnapping.
Former detective Francisco Moita Flores also dismissed the theory that the child was abducted and said the McCanns' legal challenge was "pathetic" when he gave evidence yesterday.
Mrs McCann was asked today whether she now felt it was a misjudgment to bring legal action against Mr Amaral.
She replied: "This is definitely the right course of action. I truly believe we are doing this to help the search for Madeleine.
"I believe in the Portuguese judicial system and that we will get justice, and that we can take the search for Madeleine forward."
Asked if she believed the McCanns would win their case against Mr Amaral, she said: "I am confident, yes."
Mr Amaral's lawyer, Antonio Cabrita, has denied that the former policeman said "f*** the McCanns" in response to a question from a BBC reporter about whether his book was hurting the couple.
Regional news programme East Midlands Today broadcast the exchange with the allegedly offending word bleeped out.
A BBC spokesman said: "The reply was clearly 'f*** the McCanns'.
"The entire exchange was recorded on camera, and the swear word was bleeped out for transmission as it was clearly unacceptable to broadcast such language at 6.30pm."
But Mr Cabrita said his client had not said anything in English and Portuguese journalists suggested that he said "I'm not talking about the McCanns" in Portuguese.
A judge granted the McCanns an injunction last September banning further sale or publication of Mr Amaral's book and a TV documentary he made about the case.
The ex-policeman's lawyers argue that the material in his book is contained in the official Portuguese police files for the investigation, many of which were made public in August 2008.
The McCanns, both 41, from Rothley, Leicestershire, say their main motive for challenging the former policeman is the fear that people will stop looking for their daughter if they think she is dead.
The court is hearing evidence about Mr Amaral's documentary from TV producers today.
The case will then be adjourned until a further session on February 10, when the judge, Maria Gabriela Cunha Rodrigues, will hear from two witnesses who were not available this week.
The McCanns are also seeking 1.2 million euros (£1.08 million) in compensation for defamation in separate proceedings against Mr Amaral in Portugal.
They have said any damages awarded by the courts would go towards paying for private investigators to look for Madeleine.
No date has been set for a trial in the compensation case.