Hilton McCullough, 5, of Wellington, knows how he should be smiling - his mother, Rebecca, takes a lot of photos - but to her gentle frustration he often defaults to a cheeky grin instead of the broad smile they rehearsed.
Myah, Emilie and Hilton have all battled cancer and have finished treatment or are in "maintenance mode", which requires chemotherapy pills and lumbar punctures among other treatments. And they all have the beads to prove it.
Myah easily has the most - almost 1000. She was diagnosed with Wilms' Tumour - a cancer of the kidneys - while she was in the womb and had a kidney removed as a baby. That was her first set of beads.
Five years later, almost exactly a year ago, she relapsed and began collecting a second set. She has now completely finished treatment.
Hilton, almost eight months after he was diagnosed with leukaemia, finished his intensive treatment just before Christmas. He'll now have maintenance treatment for two years.
Emilie has also just started her maintenance treatment in her battle against leukaemia, and is looking forward to her brown, wavy hair growing back.
"She loved her hair," Mrs Johns said. "For her birthday, she had a Rapunzel cake with lovely long hair."