The father of a baby born to a 12-year-old Perth girl is also believed to be a child, and police say they have no concerns for the welfare of any other children.
The girl was reportedly 11 years old when she became pregnant and the police investigation is continuing.
A spokeswoman said police were working closely with the families, the Department of Communities and the Health Department.
"There are complex social issues, which are being managed by all agencies, and the current priority is to ensure appropriate support is provided to the family," she said on Friday.
"The West Australia Police Force has identified a person believed to be the young father of the newborn, who himself is a child and is known to the young mother."
The Department of Communities said it did not comment on individual cases, but a coordinated response was required from the state government and external support agencies, in both the short and long term.
According to the WA Health Department, in 2017, three girls aged 13 or under gave birth, with a similar figure for 2016.
In total in 2017, 91 women aged 16 or younger gave birth and the youngest registered mother who was 12.
A dozen 12-year-old girls have given birth in WA since 1980.
The department says the teenage birth rate has dropped from 1.2 per cent in 1980 to 0.3 per cent in 2017.
Federal indigenous health minister Ken Wyatt said he was "troubled" knowing the young mother would not experience a normal childhood.
"She's not going to have the same journey as every one of us in this room that have gone from being a child, to a teenager, to a young adult, and then being in a position to make a better informed decision," he told reporters in Perth.
"Nevertheless, I have no doubt that her family will give her and her child support - but it doesn't make it right."
Mr Wyatt does not know the family and authorities have not revealed whether the girl is indigenous.
