Woman charged with murder after body of two-year-old girl found in Miller home

The body of the toddler was found inside the bathroom of the weatherboard home on Merino Street in Miller just after midday on Tuesday, after a family friend became concerned after she had not seen the child or her mother for several days.

The friend initially asked a neighbour for a ladder to scale a fence, before she was able to get into the house and discovered the child's body.

Detectives launched an investigation into the girl's death and, on Tuesday evening, went to a hospital in the Blue Mountains where they arrested a 36-year-old woman.

The woman was taken to Katoomba Police Station where she was charged with one count of murder. She was refused police bail, and is due to appear in Penrith Local Court on Wednesday.

A NSW Police spokeswoman said no further details could be provided about the case.

She could not confirm reports from neighbours that the girl's mother had been in a car crash in the Blue Mountains on Sunday and was being treated in hospital.

A post-mortem examination will determine how the girl died, police say.

Neighbour Patricia Ingram said a woman who claimed the be the family's next of kin had knocked on her door on Tuesday morning asking if she had seen the family.

"She knocked on my door and asked me if I had seen them and I said I hadn't seem in a while," Ms Ingram told the ABC.

The woman then asked her if she had a ladder so she could try to get into the house.

"And next the street was full of police," Ms Ingram said.

"She said [the girl's mother] had an accident ... up at the Mountains ... I presume it must have been on Sunday ... she said [the mother and the boyfriend] had a big fight and broke up on Friday."

Robyn Fransisco, whose parents live opposite the house where the girl's body was found, said a relative or friend came knocking on Tuesday morning to ask if anyone had seen anyone coming and going from the house.

Ms Fransisco's parents were told that the little girl's mother had been in a car crash in the Blue Mountains over the weekend and was hospitalised, she said.

The house remained a crime scene on Wednesday morning, as forensic police continued to examine the scene.