Schilling's husband, Gareth Brisbane, took to social media on Tuesday night to reveal the news.
"In her final moments, when I thought cancer had taken away her ability to speak, she ushered me closer and whispered a message for Maddie and me that will sustain me for the rest of my life," he wrote in a post on Instagram.
"It took all of her remaining strength, and that gesture summed up our wee Melsie perfectly. Even then, her only thought was for Maddie and me."
The public figure was first diagnosed with colon cancer in December 2023.
She announced her terminal diagnosis in March, saying her cancer had spread to the left side of her brain.
In a post on Instagram in March, Schilling said her oncology team told her "there's nothing further they can do".
Schilling became a new mum and a TV star at 42, her husband said.
"This is a woman who, through two years of chemotherapy, when she could barely lift her head from the pillow, never complained and never stopped showing courage, grace, compassion and empathy, and never missed a day of filming," he wrote.
"To most of you, she was Mel Schilling — matriarch of MAFS and queen of reality TV. To Maddie and me, she was our wee Melsie: an incredible mum, role model, and soulmate."
In Feburary, Schilling announced that she was stepping away from MAFS to prioritise her family and health, after 10 years on the show.
Her health took a turn for the worse over Christmas, when she started to experience "blinding headaches and numbness" down one side of her body.
"I honestly don't know how long I have left, but I do know I will fight to my last breath and will be surrounded by the love and support of my people," she said in March.
In honour of Schilling, her husband said: "live life to the full, love your people well, and try not to sweat the small stuff."
"I had 15 wonderful years with my soulmate, and it was the privilege of my life to be by her side. For that, I will be forever thankful."
