It has been a life-changing experience for the Mullion Creek school teacher.

"Through my work I will have a lifelong connection to them and children there are so eager to learn and listen,'' she said.

Ms Ostini has been visiting Uganda to volunteer as a school teacher for nearly three years and most of her work has been at the Parent's Care Infant slum school.

"The Twekembe project has been set up by a group of Ugandans who are in the Makindye district in Kampala. Their vision is to help lift people from poverty and improve the standards of sanitation and overall welfare of people living in the slums of Kampala," she said.

"The project allows orphans and children from poor families to go to school and gain an education. Out of the 304 children who attend the school, 216 of them are orphans."

The school mentor, who also helps at Mumbil Public School near Wellington, said the experience was challenging but had moved her to do more.

The city council visited the school earlier this year and explained they needed to work towards replacing the wooden buildings with brick structures otherwise the school would be closed.

When the school teacher returned to Australia she made a goal to raise enough money to build a new classroom for the slum school. She conducted various fundraising events at Mullion Creek and Mumbil Public School, where she works as a casual teacher. 

She taught the Australian students facts about Uganda, introduced cultural craft activities and games common in the African country and organised barbeques to raise funds for the school. 

Ms Ostini was amazed at the generosity shown within the Mullion Creek and Mumbil communities.

Through these events, Chelsea was able to raise $1270, the equivalent of three million Ugandan shillings.

"I returned to Uganda in September this year and used the money to organise and purchase materials to build two brand new classrooms and an office for the headmaster," she said.

"The materials were purchased locally and men from the Twekembe community who volunteered to help with the construction. This also allowed the school to continue operating without the pressure of the city council."

A local company made a steel five-seater round swing and see-saw for the school.

"It was my last day there and it was a complete surprise for the children and teachers," she said.

"The students were absolutely ecstatic when they saw the truck coming towards their school with the colourful equipment on the back. They jumped and danced for joy and were so excited when the equipment was lifted off the truck that they all piled on the swing at the same time."

The children in the infants classroom at Mullion Creek also donated their coloured classroom pencils to the children in Uganda.

"I took the bag of pencils to the slum school, there was only enough to give one pencil to each child. The children were so delighted to take their pencil home, they held it in the air and sang a special thank you song to me," she said.