Witnesses said the mother was heard screaming "My babies, my babies" after the horrific crash.
"All you could hear was (the mother) crying and saying, 'my babies, my babies'," a witness told 9 NEWS.
Dozens of people attended a candlelight vigil last night to honour Indie while her eight-year-old sister and 57-year-old grandmother were treated in hospital.
On Sunday night, a GoFundMe page was set up for Indie's family to cover funeral costs and medical expenses.
"The local Yandina family Jas and Emily Armstrong have lost their precious daughter Indie who was only six years old. Their eldest Lily has suffered leg injuries and is in hospital currently getting treatment," the page states.
"Emily's mother Sandy was also critically injured and is currently undertaking numerous surgical procedures.
"They are small business owners (North Buderim Butchery) on the Sunshine Coast and really just need some time to grieve and get through this extremely hard and heartbreaking time ahead of them."
Before 8am this morning, the page had raised half of its $20,000 goal.
Indie's sister Lily was struck in the lower leg but police say she was fortunate not to receive life-threatening injuries.
More than 50 people attended the vigil last night, held across the road from where the tragedy occured.
A number of locals said they'd held the vigil to let the Armstrong family know the community was there for them.
Witness Sandy Singh said it appeared the elderly driver hit the accelerator instead of the brake and lost control of her car.
"The car went like a bullet through the people on the pedestrian crossing," he told The Courier-Mail.
"There was a big bang when the car hit the pole and people were just screaming. Everyone just went crazy."
The elderly driver was uninjured but is in shock and is assisting police with their enquiries.