In "When Mommy Came Home," the "adventures" between mother and son during the treatment help drive the book forward and show readers that the little moments are what helped them get through the ordeal.
"He had always wanted to wear a [beanie] that he saw his older cousins wearing, so when I lost my hair, we wore matching ones," she said.
When her taste buds changed, Marion-Rawlins recommended her son "eat everything Mommy can't eat anymore," and after her treatment, when her body ached so much she couldn't walk to her bedroom upstairs, she and Trey pretended to be in the wilderness and "camped out" in their living room.
But Marion-Rawlins said although the book is a team effort, her son really takes the spotlight for his proactive attitude that was initially triggered when more and more families began to share their stories, asking Trey to talk to other children about his experience. When the mother of Trey's friends across the street was diagnosed with breast cancer last year, Trey was more than willing to talk to them about what he was going through.
Karen Underwood, aka Nurse Karen, told ABC News that she was "speechless" when she learned she was a character in the book. Underwood's role was to administer Marion-Rawlins' chemotherapy and "assess and take care of her."
"I think this will definitely have a positive impact on children," said Underwood, a registered nurse at Yale New Haven. "That population goes through a lot of stuff and many parents wonder what's going to happen to their children."
Trey's main focus during this time was "being brave," and Marion-Rawlins said she is "blown away" by her son's care and compassion. The young author has been asked to speak to other children and parents in the community and Marion-Rawlins said instead of getting nervous like most other kids his age, he doesn't shy away because he "knows it's going to help other moms and children."
Jennifer Quirk, library media specialist at Trey's school, said although they do have children's literature on breast cancer and other diseases, many of the material is non-fiction and "doesn't talk about real people going through the experience." Quirk said this will be the first book in the school's library that chronicles a personal experience.
"It's always a taboo subject, so having literature like this will help to make it something that parents can talk about with their kids," Quirk said.
Andrea Seigerman, LCSW, of the Smilow Cancer Hospital at Yale New-Haven, said there is still a great need for materials for "children of all ethnic groups and of all educational levels." Seigerman worked closely with Marion-Rawlins as her social worker during her treatment at Yale.
"There is a real need for easily understandable, easily communicated information from parents - both mothers and fathers going through cancer treatment – to children," Seigerman, who was with Marion-Rawlins since day one, said. "It touches on a universal need – the idea that a little boy or girl can look at a book and feel that they're not the only one who's going through this."
"Parents want to protect and inform them, but many aren't sure how to do that," Seigerman said. "So the most important outcome of this book is that it will help other parents feel comfortable opening up about this topic with their children."
But the mother-and-son duo's journey doesn't end here. Marion-Rawlins, who has a niece who wears a cochlear implant because of a hearing impairment, said they are currently discussing the possibilities of writing a second book about her to "provide awareness regarding that community."
"[Trey] knows what it feels like to be different," Marion-Rawlins said. "I think it's so important to share with children what's going on at a level they can understand."