London - A South African woman, who has been arrested for the murders of her three disabled children in the UK, has been described as a devoted mother who doted on them, reports said.

Tania Clarence, 42, was arrested after her 4-year-old daughter and twin boys aged 3 were found dead at their home in New Malden, south London.

The children, Ben, Max and Olivia, had a genetic condition called spinal muscular atrophy that left them with little muscle strength.

Neighbour Joy Devis, 86, told the UK’s Mirror newspaper that Clarence and her husband were “dedicated, loving parents who doted on their children”.

But a friend of the South African woman told Eyewitness News that she was struggling to cope with the children’s illness.

Clarence’s husband, Gary, was in South Africa with their other daughter, 8-year-old Taya, at the time of the murders but is flying back to the UK.

Gary, who works for Investec, would never have left the UK if he had known his wife was going to battle, a family spokesperson told the Cape Argus.

The UK’s Daily Mail reported that Tania Clarence had given up her career as a graphic designer to look after the children. The couple had also renovated their R21.3m mansion and installed special features, including a lift and ramps.

They employed a nanny and carers for the children and also sent them to a special school for disabled children.

The three children were found in their upstairs bedrooms and police suspect they were suffocated.