Elke Barber, 37, of Gorebridge, based the book on conversations with her son, Alex, who saw his father, Martin, die of a heart attack at age 34.
She had been saving money to publish Is Daddy Coming Back In a Minute? when she was diagnosed with breast cancer.
Her new partner, John Thompson, had to stop work to look after her children because she was so ill after undergoing chemotherapy, and her savings are being eaten up by everyday living expenses.
She is now hoping to fund the book by gathering donations on the crowdfunder.com website, which gives participants a limited time to raise a set amount, and she is building support before the launch with the Facebook page.
She said: “One of my friends put the seed of setting up a Facebook page into my head yesterday.
“Within less than 24 hours, it received over 230 ‘likes’.
“I knew this book was needed, just from talking to other young widows desperate to find a book to read to their young children, from local pre-school and primary school teachers, and local child bereavement charity Richmond’s Hope, but I have been completely overwhelmed with the response.”
To find the page, search for Is Daddy Coming Back in a Minute? on Facebook.