Before she took her last breath Diana Sevealii kissed her baby daughter's cheek three times.

"Di passed away peacefully," brother Benna Sevealii said.

"We were all in her room. She was struggling to breathe so we brought Brooklyn to see her. She kissed baby and then Mum. Seconds later she drifted off and that was that. It was her last breath."

Six weeks ago doctors told Diana, 36, she had stage four cervical cancer and had "weeks to live".

Diana spoke to the Herald on Sunday where she revealed the health battles both she and Brooklyn faced.

Brooklyn was born with a hole in her heart requiring surgery at Starship Hospital in Auckland. (Photo / Supplied)

More than $40,000 has been donated to a Givealittle page to assist with Brooklyn's care and treatment.

"Our family wants to thank Auckland Starship, Heart Kids and all the friends and strangers who have rocked up to the hospice and hospital – it's absolutely amazing a community has come together and done that for our family and Di," Benna Sevealii said.

Annie Cunningham, a former nurse and a family worker from Heart Kids – the organisation supporting the family - said Diana "knew she was going".

"It happened very quickly, we had a Christian dedication for Brooklyn on Saturday night at the Mary Potter Hospice and she was gone by Sunday night.

Diana Sevealii wanted her daughter Brooklyn with her for her final moments. Photo / Mike Scott

"She got more tired as the days went on and she was struggling to breathe. She was still joking and laughing with her brothers and sister on Sunday afternoon. She went to sleep and stopped breathing. She passed away at 7.30pm."

Baby Brooklyn and Diana's older sister Moira Peet stayed with her at the Mary Potter Hospice in Wellington.

"Di wanted Brooklyn to be with her - that was an absolute focus. She wanted Brooklyn to be with her right to the very end – it was Di's way," Cunningham said.

Last month Brooklyn had a three-hour operation to unblock a valve in her heart to allow blood to be pumped into her lungs. Her heart condition is life threatening and the family hopes she will have open heart surgery next month.

"We had some recent scans and they showed Brooklyn was deteriorating. But we had to wait for her to grow and gain some weight. She is over 4kg and growing at an alarming rate," Benna said.

Once Brooklyn recovers from surgery she will wing her way to New York where she will be cared for her by Diana's sister Moira and husband Evan.

"Brooklyn will be here while her heart heals. But when she's better Moira will make a move to New York" said Benna.

"I will always miss Di, she was a constant, she was always there to the point we all took her for granted. Now she's gone there is a massive hole in my heart."

Diana's funeral will be held on Friday at 10.30am at the Porirua Elim church.