Maxine Rock, center, with her grandchildren and co-authors, Rachel Schiffer, 12, at left, and Julia, 9. The three collaborated on a book titled “Adventures in Faun Forest.”

They started out simply as bedtime stories. Maxine Rock would spin her yarns before tucking in her two granddaughters for the night.

“When the girls were growing up, we always spent of a lot of time together,” the Buckhead writer said. “I ran out of things to read, so I started making things up.”

Soon the girls were joining in. Julia Schiffer, who’s 9 now, and Rachel Schiffer, who’s 12, began to add their own contributions to their grandmother’s stories. The three of them created their own fantasy world.

“I was the idea maker,” Julia said one recent afternoon as she and her sister sat on a couch in their Buckhead home with their grandmother to talk about the book. “I added a few ideas. At one point, there are poems. I did the poetry.”

Rachel came up with ideas for illustrations.

“My daughter thought it would be a great thing to write these down for the kids,” said Rock, who’s already published books such as “Totally Fun Things To Do With Your Cat,” “Totally Fun Things To Do With Your Dog” and “The Marriage Map.” Rock thought others might find their made-up bedtime stories appealing, too, after she realized her daughter and son-in-law occasionally were listening in at the bedroom door during story time.

In January, Rock, Julia and Rachel published their stories in a book titled “Adventures in Faun Forest.” Their book was released with a party at an Alpharetta printing house that prints books to order. About 70 to 75 people attended, Rock said. The gathering attracted friends, neighbors and students from The Galloway School, which Julia and Rachel attend, she said.

Fauns, it seems, make up a big part of the stories in their book. “Why fauns?” Rock asked. “We wanted characters who were hybrids because everything in the faun forest were hybrids.”

In other words, to hear the three authors tell it, they’ve invented a world where every animal is a bit mixed-up. “We made things up out of animals that already exist or were imaginative,” Julia said.

“Imaginative?” Rachel asked.

“Imaginative,” Julia said.

Well, imaginative or imaginary, their animals sound like few others. Their stories are populated with panthapusses (part panther, part octopus), furtles (part fox, part turtle) and zee-zees (part zebra, part chimpanzee).

“I can make up a story on my own, but it was easier when I was working with my sister and my grandmother,” Julia said. “It felt like a big accomplishment.”

“It is a big accomplishment,” said Rock, who says “Adventures in Faun Forest” is her 10th book altogether.

So, how many for the granddaughters?

“Well, do you include books published in class?” Julia asked.

No.

“Then one,” she said.