Little Lana was diagnosed with a rare and fast-growing type of brain cancer called ATRT last year.
Her engaged parents Gemma Nixon, 34, and Andrew Haswell, 40, have quit their jobs to care for the tot while she suffers the “horrendous” side effects from chemotherapy, which include vomiting blood and severe nosebleeds.
Lana’s three siblings, Neve, 16, who shared her prom night with the tot, Ellie, 18, and Jonah, 8, have been watching her bravely fight the disease without complaint.
Gemma from Hetton-le-Hole in Sunderland told Chronicle Live it was wonderful to see her youngest daughter looking like a happy princess after months of hell in hospital.
She said: “It was so emotional for us all to be together as a family and for Lana to be part of her sister’s special day.
“She loved the car and said her and Neve were princesses that day.
“It was very emotional to see Lana looking so well and in a lovely dress after months of gowns and pyjamas.”
Sheb Ahktar, 36, director of chauffeur service Autograph Prestige, drove the sisters to prom in his Rolls Royce.
“On the day, Lana was so happy, smiling and active just like any other three-year-old,” he said.
“It’s just heartbreaking. I can’t imagine what the family are going through and I’ll make sure that I will help in anyway so the family get what they need for Lana.”
Praising her little girl’s incredible resilience, Gemma added: “We cannot believe her strength and bravery.
“She is a happy, loving and funny little character.
“She deserves the world for all she has endured.
“Throughout it all she was so resilient and so tough, she would just accept it all.
“She still found time to smile, laugh, play and love.”
Gemma said poor Lana “suffered every possible side effect” of chemotherapy, which was administered directly into her brain via a surgically-fitted reservoir.
“She vomited blood, horrendous nose bleeds, her mouth broke down and bled, she was so poorly,” the mum said. “We spent a lot of time in isolation.”
Thankfully, a scan on July 4 showed that the tumour is responding to the treatment.
A family friend has set-up a Crowdfunding page for Gemma and Andrew here.