"Nicole: today you are 8 months, 26 days old - the same age your brother, Dylan, was when he passed away from SIDS," she wrote. "He never reached 9 months old, so I pray and hope you will make it past this day."
In her post, the Bakersfield, California mom opened up about her fears of losing her daughter just like her son.
"Sometimes, I am consumed by my fear that lightening can strike twice. I watch you sleep and touch your arm just to see you move to prove to me that you're still breathing," Brandt wrote. "I want to live free from the burden of fear, but losing Dylan was the worst moment of my life and I can't fathom going through it again if something should ever happen to you."
SIDS affects 3,500 children in the U.S. yearly, according to the Centers for Disease Control and Prevention. SIDS is often the result of health issues that affect infants while they sleep or conditions around their sleeping area, such as soft bedding, pillows, objects or becoming entangled in cribs.
But the deaths are often listed as unexplained. Such was the case for Brandt's son.
The mother told ABC News she was "naive" about the ordeal.
"You think, 'Oh, that's not going to happen to me.' You hear these stories of people who've lost children and you think, 'That won't be me,'" Brandt said. "But now I'm very aware that you can lose a child.”
“It literally is the worst feeling in the world," she added.
Brandt said she found comfort in the positive reactions to her post, which have been read by thousands of people.
"I had such a huge response [from] it," she said. "No one talks about infant loss. They're afraid people are going to be uncomfortable.”
Since losing her son two years ago, the mother of three daughters said she's changed how she parents. Although her son Dylan didn't die because of his crib conditions like most SIDS deaths, Brandt still said she now uses a sleep monitor for her daughter and has removed toys and blankets from Nicole's crib. Instead, she dresses her in a wearable sleeping blanket.
"It's just changed my perspective," Brandt continued. "It sounds so cliche, but I take in every moment more and I look at it like this could be my last moment with them."
She said that even in moments of frustration, she stops to think. “I say, 'But what if it's the last thing I say to them? I want it to be, "I love you, have a good day.'"
Brandt credits her faith and counseling with helping her to overcome her fear while parenting her newborn daughter. She and her husband decided to have another child through in-vitro fertilization, but she says it wasn't because she was trying to replace Dylan.
"I always say she didn't erase the pain, but she helped ease it. When I look at her and she smiles and she giggles and I'm playing with her, it makes me happy," Brandt explained.
"I'll be honest, there's always a twinge like, 'Oh now she's doing things he didn't do,'" she added. "It sounds funny, but holding her and focusing on her, it really helps ease the loss of him."