Double murder accused to appear in court

A 34-year-old woman charged with the 2004 murder of Brisbane sister and brother April and Ian Bailey is due to appear in Redcliffe Magistrates Court on Monday.

The woman, who was taken into custody on Saturday, has also been charged with arson.

The siblings are believed to have been killed before their Deception Bay home was set on fire on May 28, 2004.

Ian, 29, had been caring for his 31-year-old sister, who was recovering from schizophrenia and working as a beautician.

Ms Bailey's daughter Violet was just four when she witnessed the deaths and was discovered uninjured at the scene by police.