Qld mum to be sentenced for son's death

A mother will be sentenced next week for manslaughter after a Queensland judge found she inflicted fatal injuries on her four-year-old son, Tyrell Cobb.

Heidi Strbak, 34, rocked back and forth in the dock at Brisbane Supreme Court on Monday as Justice Peter Applegarth ruled she wounded her son then went in search of cannabis instead of help.

Tyrell died on May 24, 2009 after two separate blows to his abdomen that caused internal bleeding and the leaking of his stomach contents, known as peritonitis.

Strbak, who pleaded guilty to manslaughter in November, will now be sentenced on December 18 on the grounds she caused his death.

Justice Peter Applegarth on Monday found Strbak was the perpetrator of Tyrell's abuse and did not seek medical help to avoid a child protection investigation into his "constellation of injuries".

"She deserves to be sentenced to a very substantial term of imprisonment," Justice Applegarth found.