Brian Laundrie's mother has broken her silence on the "burn after reading" letter Gabby Petito's parents are seeking in a Florida lawsuit following their daughter's death at the hands of her former fiancé.

"While I used words that seem to have a connection with Brian's actions and his taking of Gabby's life, I never would have fathomed the events that unfolded months later between Brian and Gabby would reflect the words in my letter," she wrote in an affidavit filed in a Sarasota court Monday.

Roberta Laundrie, a defendant in the suit alongside her husband Christopher and their attorney Steve Bertolino, have maintained that the letter was written before the young couple left on a cross-country road trip that ended with both of them dead.

The Laundries are asking the court to deny the Petito family's request for a copy of the letter, which mentions Roberta offering to lend her son a shovel.

GABBY PETITO PARENTS' ATTORNEY CLAIMS IN COURT FILING THAT ROBERTA LAUNDRIE OFFERED TO LEND SON SHOVEL

Pat Reilly, the attorney for Joseph Petito and Nichole Schmidt, previously told Fox News Digital that he expects the court to compel its disclosure. He has seen the letter but does not have a copy, and he said he believes the contents show it was written after the couple left.

Roberta Laundrie, in her affidavit, sought to explain the context of the letter, saying it was inspired by children's books "The Runaway Bunny" and "Little Bear" and a writing exercise book she said Petito gave her son called "Burn After Writing."

GABBY PETITO'S PARENTS ADD ATTORNEY STEVEN BERTOLINO TO LAWSUIT AGAINST BRIAN LAUNDRIE'S FAMILY

"Brian, Gabby and I often joked about this book and the importance of being able to express yourself," she wrote of the latter.

Embarrassing ideas could be burned away, she argued.

"In some way, I did not want anyone else to read it as I know it is not the type of letter a mother writes to her adult son and I did not want to embarrass Brian," she wrote. "That is why I wrote ‘Burn After Reading’ on the envelope, and I knew that Brian would know what that meant. I am now appreciative that he actually kept it."

LISTEN: THE FOX TRUE CRIME PODCAST WITH EMILY COMPAGNO

She claimed that she sent her son a letter because she felt they were growing apart and wanted to reassure him "through a light-hearted and quirky reminder" ahead of the road trip.

"Although a few of the words in the letter are being quoted by others as having a connection to this case, all of the words taken together and in the context of the reason the letter was written show that there is no connection," she wrote.

She also aimed to dismiss speculation that the letter had been in her son's dry bag, which, as Fox News Digital witnessed, Christopher Laundrie stumbled upon in the swamp the same morning police and the FBI found their son's remains nearby.

GABBY PETITO AND BRIAN LAUNDRIE: BOMBSHELL VIDEO EMERGES SHOWING HOURS BEFORE MURDER

"There has been some speculation that this letter was in Brian's possession or in his backpack when he died – insinuating that I gave it to him as he left my home on September 13, 2021 – but that is not true because the FBI had the letter in their possession and questioned members of my family about it prior to October 20, 2021 when my husband and I found Brian's remains in the reserve," she wrote.

Laundrie left his parent's house in the rain on Sept. 13 and took his mother's car to the Myakkahatchee Creek Environmental Park, about 10 minutes away.

The heavy rains flooded the swampy park, and despite weeks of searches, police found nothing until after the water levels went down and the parents led them to a clearing that they had believed their son might have gone.

He had returned to his parents' home in North Port, Florida, on Sept. 1, driving Petito's van but with her nowhere in sight.

Police found her remains at a campsite in Wyoming, just north of Jackson, where the couple had last been seen together in public. The Teton County coroner ruled her death a homicide by strangulation and blunt force trauma to the head.

The contents of Laundrie's drybag included a handwritten confession, published first by Fox News Digital over the summer.

"I ended her life," reads the note. "I thought it was merciful, that it is what she wanted, but I see now all the mistakes I made. I panicked. I was in shock."

He claimed that he killed Petito after she injured herself when she fell in the wilderness. 

"From the moment I decided, took away her pain, I knew I couldn't go on without her," he added.

According to the FBI, he died of a self-inflicted gunshot wound.