Natalie and David Schilg flew back into Australia on Tuesday after spending a month in Colombia completing paperwork for the adoption of Camila, 9, twins Justin and Clara, 7, and youngest sibling Maria, 5.

The children have been living in an orphanage in Cali, west of Bogota in central Colombia, for five years after both their parents died of illness and no other family members could be found to care for them.

A Department of Community Services spokeswoman said the Schilgs were not the first couple to adopt more than two children at once.

“We have had a family adopt five children at once before but that was a number of years ago and it is certainly very rare,” she said.

Mrs Schilg said Department of Community Services staff told her they believed her family could handle more than two children as they were so laid back.

“We originally applied to adopt two, but it didn’t bother us how many we ended up adopting; we love having children around.”

Mrs Schilg, her husband and their youngest son Tannah, 13, flew to Colombia on Valentine’s Day and for four weeks lived with the children at an international adoption agency.

Details including birth certificate, visas and passports were sorted and Mrs Schilg said the entire family was photographed, interviewed and filmed for local newspapers, American newspapers and the CNN.

While it was an exciting time for everyone, Mrs Schilg said the first few weeks were “a nightmare”.

“The orphanage where they lived caters mainly for babies because they are adopted fairly quickly, so the older children were more or less left to their own devices,” she said.

“They had no manners, would grab food off the table and run and didn’t speak a word of English.”

Though Mrs Schilg has studied Spanish, she said the children spoke a type of slang language that was hard for her to understand.