On LEGO Masters, Marielle is all smiles alongside her teammate Kaitlyn. But behind closed doors, the digital campaign manager has suffered with crippling anxiety for as long as she can remember.
From the age of 15, she's battled panic attacks – to the point that even getting on an aeroplane to film for LEGO Masters was a challenge in itself.
"It was the scariest thing I've ever had to do," Marielle, 28, tells TV WEEK. "When I stepped off the plane I cried. I knew that if I could do that, I could do anything."
Marielle believes her anxiety stems from the loss of her father, Efren, who passed away when she was just 11 years old.
"You don't really know what death is at the age," she says. "But as you get older you realise what it is. I guess I get panicky because something like that might happen to me, or someone I know. A lot of my anxiety is health related."
Marielle says her dad, who was an architect, would be incredible proud of her appearance on LEGO Masters.
"Every day I feel his presence," she says.
She also says her family home serves as a constant reminder of her dad's talents.
"He designed our house," she explains. "Every time someone comes round and comments on how lovely it is, it reminds me of him. The same goes for the architectural sets on LEGO Masters. He was so creative."
LEGO Masters airs Monday, Tuesday and Sunday, 7.30pm, Nine