But the Port Dalrymple pupil is used to hard work, having to overcome huge obstacles just so she could walk, talk and live to her fifth birthday.

Isabelle, who suffers from chronic lung disease, started kinder last week after 12 months of preparation.

Her mother, Jessica Nicholas, said Isabelle had to take fortnightly classes run by the Tasmanian Early Intervention Service to build her immune system and help her transition to school life.

She said Isabelle suffered constant health complications as she was born 15 weeks premature.

"She basically spent the first two-and-a-half weeks of her life on life support and she spent a total seven-and-a-half months in hospital before we were allowed to take her home," Ms Nicholas said.

"The first two years of her life were pretty much in and out of hospital with chest infections and pneumonia and therapy pretty much fortnightly.

"Now she gets sick very easily, she suffers a lot - in winter mainly - from chest infections and general colds and she usually spends at least two or three weeks during a winter in hospital just on antibiotics to help her get over them."

Ms Nicholas said Isabelle's biggest struggle was her weight.

"She's extremely underweight for her age so she sees a child health nurse and GP every month for weight - she hasn't put anything on in eight months," she said.

However, she said Isabelle had overcome big hurdles to get to where she was today.

"When Isabelle was born we were given a 5 per cent chance of her surviving because she was only 25 weeks and two days and I'd had a good week of being unwell where she didn't do any growing," she said.

"We were spoken to by a team of neonatologists and were told that if Isabelle did survive, she would have massive health complications that could be anything from complete disability to mild cerebral palsy - they just couldn't tell us.

"Then when Isabelle was two weeks old we were also told because of the amount of breathing problems and suffocation that Isabelle had actually had, she would most likely sustain some type of brain injury and we were told that she would most likely never walk or talk.

"But now she runs everywhere and never stops talking."

Ms Nicholas said she never expected Isabelle to leave the hospital, let alone make it to kinder.

"It's a massive milestone - and it is actually the first one she's reached on time," she said.

"Most of her development milestones like walking and crawling were very much delayed, her speech was very much delayed, her early learning skills were significantly delayed and she has just made absolute progress in the last 12 months.

"Her first day drop-off was absolutely fantastic, we were expecting her to be very hesitant because she is so shy around other children, but she was so excited to meet her teacher and have a look around her classroom."