The Australian tourist suffered serious injuries when she was attacked in front of her 34-year-old mum on the morning of August 12.
A court heard how a man approached the girl, placed her in a headlock and stabbed her eight times.
Members of the public intervened, and when police arrived they found a man being held on the ground.
The child was taken to hospital for treatment for injuries to her face, shoulder, wrist and neck area.
Her mother was initially thought to have been hurt too, but blood from her daughter’s injuries had been mistaken for injuries, police said.
In an interview with 7News Australia, the mother, from New South Wales, said they had been on a “dream” holiday to see Swift.
They had just left the Lego store when her daughter was “jumped on”, she said.
The young victim told 7News Australia that she wanted to thank all the hospital staff for “making her feel more safe”.
She said: “It was bad to meet them under those circumstances but they are some people I will remember forever.”
With the help of Australian consular officials, after a week of recovery she was able to watch Swift perform, before returning home to Australia on Sunday, according to the report.
She added: “She’s the most optimistic kid you could meet, she’s super bouncy.”
Last week, a security guard who helped disarm the attack suspect was recognised for his bravery at the Pakistan High Commission in London.
Ioan Pintaru, 32, of no fixed address, has been charged with the attempted murder of Laila and possession of a bladed article.
The Romanian citizen is next due to appear at the Old Bailey on September 10.
Police have said there is no suggestion the incident was terror-related and officers do not believe the suspect and the victims were known to each other.