The Dubliner was once again saved from elimination as she sailed through to the next round of the competition.
But Mary says it's all down to her daughter Debbie, who for the first time attended the live London show.
"Having my daughter Debbie in the audience has given me my confidence back," Byrne said.
"I am a lot more confident this week compared to last week because my daughter is here."
The “X Factor” judges were in agreement.
"I know you are back, Mary, as I can feel it in the room," Cheryl Cole said. "It is nice to see the twinkle back in your eyes."
"You definitely have your mojo back tonight. And the end note was spectacular,” Dannii Minogue added.
During the “Xtrafactor” Debbie was invited on stage with all the acts and told the audience her mum was “amazing”.
"I was just so proud watching my mum perform on-stage. She was just amazing. Back home, it's like the World Cup. Mary fervour has hit Ireland," she said on the show.
The 24-year-old overcame her fear of flying this past weekend when she traveled to London to support her mother.
However Debbie later revealed that the hardest part of weekend would be saying goodbye to her mother and returning to Dublin.
"We're both dreading that. It's going to be like getting separated all over again but I so want her to follow her dream," she told the Irish Independent.