Kristen Leslie Olsen, 24, was charged with arson and the murder of baker Todd Mooney, 54, and his daughter, Kirra, 10, on Friday and has had her case heard in a Sunshine Coast courtroom on Saturday.
Ms Olsen is accused of lighting a shed fire on a Biggenden property, north-west of Brisbane, that was owned by Mr Mooney, on December 20.
Detectives say Ms Olsen lives an hour north of Biggenden, in Maryborough, but has connections to the Biggenden area.
Her matter was mentioned in the Maroochydore Magistrates Court on Saturday, and she is expected to appear in the Maryborough Magistrates Court on Monday.
At a press conference on Friday, Detective Gary Pettiford appealed to the public for information or vision of a white Holden Barina van with a distinctive solar panel.
Police found that car burnt out on a Maryborough road and have recovered it as part of their investigation.
They are still appealing for information regarding the movements of the vehicle.
The fire, which took several hours to extinguish, was initially treated as a tragic accident.
