A pregnant mother who had a concrete block thrown at her in a "senseless" attack in suburban Perth is fighting for her life.
Diane Miller remains in a critical condition in intensive care at Royal Perth Hospital, having suffered a heart attack when the brick was thrown through the window of her car at a shopping centre in Karawara on Tuesday night.
The 30-year-old is five months pregnant and also has an eight-month-old son. Her family has been told the unborn baby would not survive in the event of her death.
"We're destroyed, shocked. She's such a beautiful person and she would do anything for anybody," her brother Malcolm told Perth radio 6PR on Thursday.
"The family don't know if she's going to pull through. The doctor said that she's got swelling on the brain and they said it's not coming down."
A 17-year-old boy who allegedly threw the concrete block faced Perth Children's Court on Wednesday charged with grievous bodily harm and breach of bail.
He was remanded in custody.
Police have alleged there was an argument involving a group of teenagers and Ms Miller's partner, who had been driving the car.
The parties are not believed to have been known to each other.
"This is, quite simply, senseless violence by a bunch of teenagers," Inspector Brett Baddock told reporters.
"From what we can gather, it's unprovoked. I think they've gone out looking for trouble and they've found it."
Members of the public attempted to resuscitate Ms Miller before an ambulance arrived. Her family has said she suffered bleeding to her brain.
Police have urged anyone who witnessed the incident or who has dash cam vision to contact them.
