The onboard emergency unfurled on 12 April as the aircraft was over the Atlantic, about 90 nautical miles southwest of Faro.
The child, aged around 10, is understood to have sustained second degree burns to her legs after being scalded with hot tea.
The pilot made the decision to divert to Faro, where the girl and her family disembarked and were taken to a hospital.
A spokesperson for Thomas Cook Airlines Belgium told The Portugal News: “We can confirm the diversion of this flight was due to a scalding incident on a child customer.
“Safety is our number one priority and our crew immediately gave first aid and provided all support possible to the child and her family. The aircraft immediately diverted to the nearest airport at Faro, where an ambulance took the child and her family to hospital for further care.”
The airline said it is “investigating this deeply regrettable event and wish the child well in her recovery.”
Belgian media reports said early suggestions were that the hot tea was spilled by a flight attendant; however, witnesses on board the aircraft later claimed no flight attendant was involved in the accident, but a family member of the girl.
Belgian newspaper, Het Laatste Nieuws , said the young child is the daughter of Ingelmunster mayor, Kurt Windels.
On 15 April, the girl’s family said she was already at home and recovering without any permanent injuries after “initially suffering a lot of pain”.
Speaking to Belgian media, the family questioned the use of piping hot fluids on board aircraft “where the environment is unstable and unexpected movements could affect the plane at any time”.
However, the family said no legal action would be taken against the airline.
Meanwhile, days later, on Monday evening (17 April), a UK-bound Thomson flight was also forced to divert to Portugal after the windscreen cracked in mid-air.
The flight from Gran Canaria to Bristol was forced to descend from an altitude of 30,000ft to 10,000ft after the windscreen became badly damaged and the Captain made the decision to divert to Porto.
One of the 200-plus passengers on board the jet told the Bristol Post that people were made to queue for food vouchers while they waited for another flight.
“We’ve been here about two hours now. Everyone is OK but a bit fed up as we are not really being told very much about what is going on, other than being shunted from one part of the airport to the other” the passenger, identified only as Laura, said.
She added: “Nobody we’ve spoken to knows what is going on and that includes the airport staff.”
Laura said passengers were only told about a “technical fault”’ during her flight, before they learned after landing that the windscreen had been damaged.
“It was the flight stewards who told us to look at the windscreen when we disembarked,” she added.
A tweet from Thomson to Laura said: “We are sorry for the circumstances and hope you can continue your flight home soon.”