Samantha and Alex Goodwin, from Medowie, were excited when their twins Milla and Carter were born healthy just eight months ago, joining their two-year-old son Hudson.

Shortly after, the babies contracted a rare brain virus which Milla managed to fight but which left Carter with the non-progressive movement disorder cerebral palsy.

"There were lots of tears, anxiety, angst and now the unknown," Mr Goodwin said.

"But we have three beautiful children."

The unexpected diagnosis means regular testing, physiotherapy appointments, paediatrician visits and doctor's appointments for the young family, all of which cost money.

"Some of the visits are covered but if we want to increase the physio we have to pay for it. Down the track there will be equipment and other things we will also need to pay for," Mrs Goodwin said.

The Mothers' Group, friends and family members have stepped in to help them out, holding a fund-raising garage sale this Saturday, July 26.

The garage sale at 70 Bagnalls Beach Road, Corlette, will include children's toys, clothing, bric-a-brac, books and household goods. Cakes by Rachael is providing baked goods for sale, and the organisers hope to raise $1000.

Mrs Goodwin said the support from the Mothers' Group had been "amazing".

To learn more about Carter head to the family's Facebook page /CarterCrewMember.