Her latest book, launched on Thursday, is aimed at a slightly younger audience.
Fantastic Mr Bean is just delightful and marks the 50th anniversary of Roald Dahl's Fantastic Mr Fox.
The story is about Lachie who is desperate to get the part of Mr Fox in the class production.
Mary-anne said she has had the idea for the book for a long time.
"It happened to my son so that's where it came from. I think younger readers will enjoy the interplay between the brothers. It has a theme of sibling love — yes, they can treat you bad but when push comes to shove blood is thicker than water and they are there for you."
There's also something a little bit special about this book.
"I had just finished reading Fantastic Mr Bean to my 7-year-old grandson Lachie to see if he got the concept.
"He said to me 'why can't that boy be called Lachie'. I said 'he can be'. He's delighted."
Mary-anne is passionate about keeping children reading. "Kids need to learn about hope and resilience and reading about it is one way to do that."
Mary-anne is also a talented musician and speaker. She visits schools talking to different classes.
"It's a rewarding thing to do. These kids need to know that their stories are important."
The illustrator of Fantastic Mr Bean is Lisa Allen, from Auckland.
"I met her at a workshop run by Joy Cowley, on writing picture books. We kept in touch and she submitted some ideas to my publisher, OneTree House, and they agreed she could have the job of illustrating this book.
"She has a son, a bit older than Lachie and she asked her son to pose for the front cover, wearing Mr Bean clothes and holding his toy gun. I asked Lachie to look grumpy and took a photo of that to capture the mean Mr Bean look. Lisa put Lachie's face onto Rory's body. When her son saw the finished cover, he was shocked and said, 'What? That's not my face!'
"It was great working with an illustrator — it added a new dimension to the telling of this story."
Mary-anne says she still gets a buzz when her finished books arrive on her doorstep. "It's so exciting, a bit like having another baby," she laughed.
She says her best asset is her sister Jude who edits all her copy. "She hears the essence of the story and calls me out on stuff. She's so honest— she has saved me hours of going down the wrong path. I'm so lucky to have her input."
The Fantastic Mr Bean is available from Wardini Bookshops.