Hayley Tapu, one of the unofficial organisers on behalf of the families affected, said it was great to see all the families at the sanctuary "with smiles on their faces".
"[Being here today] means quite a lot, really," said Mrs Tapu, whose son is buried at the site, although his grave was not one of the ones destroyed.
"Joy's absolutely outdone herself, her work is amazing. We saw pictures of what it might look like, which looked great, but you couldn't picture it being that amazing."
Mrs Tapu said she was glad the saga had come to a happy conclusion.
"There's a sense of peace, of peacefulness now every time I come down."
Monica Snook, another parent and advocate on behalf of families affected, said she too was happy with how the new space had turned out.
"Working with [the council] I think they have pulled through and it's been a big improvement, even better than before it happened. It's an area you feel happy coming to see."
Ms Bell said she had designed the wall with children and parents in mind.
"It's whimsical and was definitely geared toward babies and their siblings."
The wall features benches where parents can sit and reflect when they come to visit their babies' graves, with a range of objects pressed into the side of the wall for children visiting to interact with.
The wall is divided into distinct sections.
"It became logical to group it," Ms Bell said. "You start off at the sea and then you go into the garden which gives you animals and birds and then you go into the formal living area which is a home away from home for the babies."
Ms Bell said the piece had meant more and more to her as she worked on it longer, getting to know some of the families along the way.
"It's been wonderful and I've often thought, if this was my last job, what an amazing swan song, what an amazing last piece [it would be]."
