"This s**t is real. Get fully vaccinated as soon as possible so no more families have to go through this nightmare," she said.
Deputy Premier Steven Miles said it was "heartbreaking" to see how many children were embroiled in the latest coronavirus outbreak.
Five of Queensland's 10 new community cases today were children.
"I think when you read those heartbreaking stories of parents caring for their children in hospital with Covid-19, it brings home just what it is we are trying to avoid," Miles said.
Spencer and her husband, who have both received one dose of the Pfizer Covid vaccine, also tested positive to the Delta strain yesterday afternoon, which had only compounded their daughter's fear.
First reported by the Courier-Mail, Spencer said her daughter was "scared her parents might die" after seeing them struggle with the virus.
"When our precious poppet tested positive for Delta, we were in disbelief initially, and it truly broke our hearts," she said.
"At 4.30am the next morning, the ambos came to take her to hospital and I went with her.
"It was pitch dark and there was a lit-up escort and medical staff in PPE; it was like something out of a movie and very confronting for a little person, but my daughter just said her bunnies were scared and she was trying to be brave."
Spencer has been sharing a hospital room with her daughter since Monday.
"She has deteriorated slightly in hospital with a sore throat and fatigue so we're hoping that plateaus. With so many now of our school community affected, she doesn't feel so alone," she said.
"The Ironside State School community is truly fabulous and we've had incredible support from families going through their own stress of quarantine and awaiting test results for their little ones."
Queensland's chief health officer Dr Jeanette Young revealed earlier this week there were a large number of children in hospital with coronavirus.
"They are not particularly unwell," she said yesterday.
"But they need to be in hospital and thank goodness we have got ... one of the best hospitals in Australia for children, so I am very confident that we can manage them there or in one of those other hospitals that have now had a lot of experience in managing Covid in children."
Young said the children were in hospital as a "precautionary measure" but they "do need to be there".
Some children are being cared for at home with Queensland Health's hospital at home measures.
If children did need to go into hospital, their parents went in with them and quarantined for 14 days, Young added.