A Victorian children’s court has heard the girl, now 15, would smash the windows of cars and then take what she could.

On one occasion she was accompanied by a 16-year-old boy.

Both pleaded guilty yesterday to crimes related to the break-ins, though the girl faced more than twice as many charges as her accomplice.

While pleading guilty to just a few incidents, she told police she had probably broken into between 25 and 50 cars.

Some of the charges related to attempts by her — on separate occasions — to use a cigarette lighter to set fire to a wall and a couch in the supported accommodation unit where she lived.

She did this because she was “frustrated”.

On October 17, she walked to a car parked in a street and smashed a window, grabbing what she could from inside.

And on November 24, the girl — accompanied by the boy — smashed a car window and stole a set of butcher’s knives, which were later recovered from her bedroom by staff of the unit.

The pair stole a satellite navigation system — later buried — and five CDs from another car a few weeks earlier, on November 7.

The girl’s solicitor said she had had “a fairly sad history”.

Her behaviour had deteriorated and become difficult since she was placed under the guardianship of the state, resulting in her being moved to between 15 to 20 towns across Victoria.

“It seems clear that this person needs help,” the solicitor said.

The magistrate ordered pre-sentence reports on the pair who will return to court on March 26.