Claire Colebourn, 35, was arrested earlier this week in connection with the child’s death.
Police and emergency crews descended on the family’s home in the U.K. Thursday night responding to a reported concern for someone’s welfare, according to Metro.
Neighbors said Colebourn lived in the upscale home with her daughter, Bethan, and 37-year-old husband, Michael.
Paramedics treated the girl at the house and then flew her by air ambulance to a hospital where she later died.
Claire Colebourn, who had been a science teacher and later a private tutor, was taken from the home by officers.
One neighbor told The Sun that he had visited the family’s house last Christmas but hadn’t seen them very much since.
“I cannot believe what has happened,” said the neighbor, who declined to be named. “Claire and Michael were nice people and they had a lovely little girl called Bethan.”
Michael Colebourn graduated from the University of Southampton in 2003 with accounting and finance degrees. He joined the company Trimline in July 2015 and was later appointed its chief executive officer. The business is in the interior renovation business and generated more than $47 million last year.
Michael Colbourn is reportedly an avid sportsman who participates in triathlons and plays football, golf and tennis.
A woman who attended a baby group with Claire Colebourn said she thought Colebourn was a “lovely woman.”
“I ride my bike past their house a lot and if I ever see her she always says hello to me,” the woman said, noting that there are often two vehicles in the home’s driveway.
As is typical in the UK, authorities have not released any photos of the suspect.
A spokesman for an ambulance service said an adult patient was treated at the scene but was not hospitalized.