"I went to do my regular 10-15 min check on her and I heard the hairdryer going," she wrote in an emotional online appeal,
"I raced in to find she had fallen off the bed and turned on the hairdryer that was on the floor but she then somehow rolled on her back and couldn't roll back. With the hairdryer on her she has suffered 2nd and 3rd degree burns on her head and down her neck."
Dannielle screamed for her husband to call an ambulance as she rushed the tiny tot to the shower, where she ran cold water over the burns and comforted her on the breast.
"I looked at her head and I knew it was bad," she told The Advertiser newspaper.
"I didn't even know, when we were in the ambulance, whether her tiny little body was going to be able to cope with a burn like that, and if she was going to pass away on the way to the hospital out of shock or something," she said.
"It was terrifying."
At the hospital, family sang to Sienna to calm as nurses worked to cool her burns.
The serious burns left Sienna's head so swollen that she went blind for three days.
She has now had one surgery but faces many more operations, including a skin graft, and it is likely that sections of her hair will never grow again.
The family posted details of the accident in a GoFundMe appeal, revealing that they "feel like the most horrible parents in the world".
"We, as her parents, are shattered that anything like this could happen to our little angel," Dannielle Robbins wrote, revealing the couple were "emotionally drained from the pain we see our baby in constantly".
"We have cried for days on end for our little girl and wish we could take her pain as our own."
The appeal, which has already raised over AUD$11,000, is designed to allow the parents to stay off work to care for Sienna.
