"We started seeing a difference between the two girls once they were around 6 months old, Violet started to talk and stuff then she just started slowly declining, she'd not sit up, or she'd stop rolling, or talking, and now she can't sit up at all."
Miss Bell runs a photography business, Photography by Nikki, and has started a fundraiser for Violet called "bring your child's artwork alive".
Parents send Miss Bell two photographs, one of their child pretending to paint in the sky and another of their artwork, Miss Bell edits the photographs together.
Money raised from the project will go towards a P-Pod for Violet, a special chair that provides support for disabled children and adults.
Miss Bell said although she feels she cannot do anything to help Violet's condition, fundraising to make Violet more comfortable is "better than nothing".
"This is the only thing that I can do, so I'll do it if it's going to help.
"She's just an awesome, amazing little girl."
She has also started a Facebook page called, Help raise funds for Violet's P-Pod, and said $145 of donations have been given to Violet's family so far.
"We're just starting, so it's better than nothing."
Miss Bell is organising a sausage sizzle, which she hopes will be held at the Masterton Warehouse, and said other friends of Miss Hooper's are organising car washes, and cupcake decorating classes in Lower Hutt and Stokes Valley, where the family live.
She last spoke to Miss Hooper yesterday morning and said Violet was doing well and would be going back into hospital on Friday for an operation to get a feeding tube, as she has trouble swallowing.
She said the diagnosis was still sinking in with Miss Hooper and Mr Stephen, who found out in July Violet had Tay-Sachs. "They are really amazing people and they are really, really strong."
