She is now a bubbly six-year-old and well on her way to over coming some of the challenges life has thrown at her.
Her parents, Dawn and Ally Colhoun, got involved with an organisation called 'Wouldn't Change a Thing' which hopes to alter people's perceptions of Down Syndrome.
"My daughter Maisie entered our lives with a bang at Altnagelvin area Hospital where I worked as a Midwife Support Worker," explained her mum, Dawn Colhoun.
"I had grown up with our neighbour’s little girl who just happened to have Down Syndrome, so we were more concerned that Maisie had a rough start to life and was extremely sick from as soon as she was born due to two holes in her heart."
Dawn say's her daughter 'lights up a room' with her beautiful smile and kind and affectionate personality.
But she also has additional needs that can make life more difficult for her.
"Maisie has a moderate to severe learning disability, she is extremely loving but needs her own space too," smiled Dawn.
"You will get hugs and a kick in quick succession. She has sensory needs above other children and her peers.
"She lights up a room and gives hugs to random strangers whilst out walks.
"She has a fab laugh and mischievous character, a pure heart and a fantastic diva personality.
"Maisie amazes us everyday”
Maisie has taken longer to reach some of her developmental milestones and recently learnt to take her first steps at the age of six and a half.
"The fact that it takes her longer to learn things is a blessing it makes you appreciate all the little things and our family and friends of Maisie wouldn’t change a thing about her she makes life interesting and fun.
"Maisie has taken longer to learn things like sitting up and walking but nothing will stop her once she learns what to do.
"She loves her two big brothers Thomas and Christopher and they are mad about her, as are their friends. "
When Dawn and Ally need advice or help they turn to family and friends, Foyle Down Syndrome Family and the 'Mummy
Group' at Ardnashee School & College.
Recently the Colhouns got involved with 'Wouldn't Change a Thing' who went viral after 50 mums whose children have Down Syndrome recorded a special video.
The family were then asked if the charity could feature Maisie in their new book to reassure parents there are friends out there to support their journey every step of the way.
Dawn said she wanted new parents of children with Down Syndrome to know they are like any other child.
"Maisie and her friends are like everyone else they want to learn, succeed, have friends and have adventures along the way.
"This book proves they do, and they should be celebrated because what we take for granted, they work very hard at.
"It will show new parents not to fear what’s to come, but to celebrate every step of the way.
"It will show fun, love, excitement and families who love and adore their kids.
"A life with a child with Down Syndrome brings ups and downs like any other child but it brings love and happiness and celebrates the triumph of achieving every little thing, of taking time and appreciating everything in life it also comes with the usual behaviours, tantrums, mischief making and everything other kids do.
"This is a book to prove positive lived stories of kids and adults with Down syndrome and dispel the fear of what’s to come, with outdated perceptions of what life is like.
"Maisie lives life to the full and we will encourage her every step of the way.
"This book is a celebration of her and her friends."
The book shows people with Down Syndrome of different ages and ethnicities at different developmental milestones; some of whom have medical issues too.
"This is the book all my friends and family wish they had seen when their children were born with Down Syndrome," continued Dawn.
"It would have been lovely to have had a book like this to show to siblings too.
"It will help to show new parents our kids are the same as everyone else, some do things slower than others, but they all get there in the end.
"You just need to enjoy the journey and rely on the huge network set up with wouldn’t change a thing and family and friends are there to help every step of the way."
The beautiful pictures of Maisie, who turns 7 next month, that feature in the book were taken by local photographer Leisa Smith-Anderson at her studio in Altnagelvin Industrial Estate.
"Leisa was just amazing and Maisie remembered being at her studio before, although she did create mischief at the shoot climbing on the seat and trying to throw it over," laughed Dawn.
"Our family is stronger with Maisie and we wouldn’t be without her."
You can order the book from www.wouldntchangeathing.
If you have a story or want to send a photo or video to us please contact the Derry Now editorial team on 028 7129 6600 for Derry City stories Or 028 7774 3970 for County Derry stories. Or you can email [email protected] or [email protected] at any time.