Donations to help the family of schoolgirl Alexis Dean, who has died two days after being badly burnt in a house fire, are hurtling towards the $20,000 goal.

The crowd funding has leapt from $4000 to more than $12,000 in 24 hours, with one family alone tipping in $3000 assist the Queensland family that lost everything in the blaze.

"Rest in Peace Alexis your (sic) one little fighter," wrote Sean, Kenan, Darren and Annette Spriggs.

Family and friends have expressed grief over the loss of Alexis, who died on Wednesday after firefighters pulled her from a blaze that engulfed her family home on Monday.

The 12-year-old was trapped inside a bedroom when the Monkland home, in Gympie's south, caught fire and firefighters had to risk their lives to pull her out.

Her mother and two other children were able to escape.

Premier Annastacia Palaszczuk took to Twitter to convey her condolences to the family, which has requested privacy.

"The thoughts and prayers of Queenslanders are with the family and loved ones of Alexis Dean. Such a tragedy," she tweeted.

Alexis died at Brisbane's Lady Cilento Children's Hospital and her family said her organs have been donated to help others.

"We are grateful that Alexis was able to donate her organs and give life to others, and this was in keeping with how she always wanted to help others," the family said in a statement.

The news has seen an outpouring of grief on the Facebook page of Alexis' sister, Kara.

"She will live on in our memories," wrote one friend, while another wrote "words can't explain how much pain I'm in."

Firefighters are yet to determine what caused the fire but have said it started in one of the home's bedrooms.

© AAP 2016