A woman has been charged with murder over the deaths of a Queensland father and his 10-year-old daughter five days before Christmas.

The remains of Todd Mooney, 54, and his 10-year-old daughter Kirra were found after a shed fire at Biggenden, south-east of Bundaberg, on December 20.

The local bakery owner was due to marry his fiancee on December 28.

Investigators initially believed the pair died in a tragic accident before autopsy results steered police to treat the incident as a homicide.

Police have charged a 24-year-old Maryborough woman with two counts of murder and one count of arson.

Detective Chief Inspector Gary Pettiford would not comment on a possible motive, or what led to Friday’s arrest.

“We don’t believe that she was known to either of the deceased, or Rebecca, Todd’s fianceé,” he told the ABC.

“We still have a hell of a lot of work to do, and it’s all quite sensitive.”

The woman is expected to face Maroochydore Magistrates Court on Saturday.

Investigators are appealing for anyone who may have seen a white Holden Barina wagon with a distinctive solar panel on the roof in the area around the time of the fire to contact police.

-with AAP