And they have spoken about the children, describing each of their personalities and what they will be remembered for.
Six-year-old Liané and her 2-year-old twin sisters Maya and Karla were found dead in their Timaru home on September 16.
Their father Graham Dickason arrived home from a work function to find his little girls dead.
She was rushed to Timaru Hospital, where she was stabilised and treated.
The night after the girls were found, she was charged with three counts of murder.
Lauren Dickason was remanded to Hillmorton Hospital in Christchurch for a psychiatric assessment.
She will reappear in the High Court on Tuesday, likely by audio visual link.
Details of a funeral for the young victims are yet to be made public.
Last week Graham Dickason, who moved his family to Timaru to take up a role at the hospital as an orthopaedic surgeon, said he had forgiven his wife.
"I honestly believe she is a victim in this as well," he said in a deeply moving letter he penned to be read at a vigil to mark a week since the alleged murders.
"I have already forgiven her and I urge you in your own time to do the same ... it is the key to healing this loss we have all experienced."
Graham Fawkes did not want to speak in-depth about what had happened to his nieces but shared photos taken at a "celebration" of the girls earlier in the day.
"We love them and we will always love them," Fawkes told The New Zealand Herald.
He said the gathering was held in Pretoria at a public space.
It was "more for family and close friends" but some members of the public also attended.
Three photos of the girls were lined up in a grassy area near a small pond.
The photos bore the children's names and a description of each of them.
"A beautiful little girl inside and out. You were such a chatterbox with an infectious laugh," Liané's read.
"You were so creative and loved your stickers and sparkles.
"You were kind and always cared deeply for those around you.
"You were a loving sister with a soft heart."
Karla was born with a cleft lip and her grandparents said last week she did not have the best start in life - but she overcame that and was brave and an explorer.
At today's service she was described as "a beautiful little girl who was feisty, independent and strong".
"Yet, kind and caring," her photo caption read.
"You loved a cuddle and loved early mornings.
"Your smile left an impact on each person that met you.
"You were such a cheerful and happy little soul, your little personality was contagious."
Maya was remembered as "a beautiful gentle little girl who was always smiling".
"And a real little charmer who knew just what look to give us to get one more sweetie.
"Playful to the core, so happy and cheerful - you loved tea parties and perfected the pinkie finger."
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
OR IF YOU NEED TO TALK TO SOMEONE ELSE:
• LIFELINE: 0800 543 354 or 09 5222 999 within Auckland (available 24/7)
• SUICIDE CRISIS HELPLINE: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• YOUTHLINE: 0800 376 633 ,free text 234 or email talk@youthline.co.nz or online chat.
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757
• SAMARITANS – 0800 726 666.
