Kelly said having another baby would help the family heal from the loss of Isla, especially Sofia who talks about Isla all the time.
"She had to watch her little sister die when she was 4. She was old enough to understand what was going on," she told the Herald on Sunday.
"For us it's putting something to rights, it completing our family, it's helping us heal.
"We've been through so much, we've had everything thrown at us. It would be an amazing gift for someone to give give us."
Time had done little to dull the terrible pain of losing their baby.
"Every day I grieve for my beautiful daughter and for my family, every evening I light a candle for her and every milestone that passes becomes harder as the enormity of what we lost hits home again and again."
The couple are looking for a gestational surrogate — a woman to carry Kelly and Yanakopulos' fertilised embryo.
It is the second time the couple have sought a surrogate.
In 2015, Kelly posted of the family's plight on Facebook and were contacted shortly after by a woman offering to help.
Over a year they built a relationship, and approval from ethics committee ECART for the surrogacy to go ahead.
But last November, just one week away from transferring the embryos, communication between the two parties broke down.
"We don't know what went wrong. We never got an explanation from her which is really difficult," Kelly said.
"We just thought, 'Come on when is the universe going to give us a break'."
After they "licked their wounds" for a few months the couple are ready to put themselves out there again to find a surrogate.
Prior to seeking a surrogate the couple have undergone four unsuccessful rounds of IVF.
Kelly doesn't have any specific requirements for a surrogate, just someone who is "easy going, outgoing and has similar values and beliefs to us".
"Until you meet the person and start this journey you don't know where you'll end up."
An investigation into the birth of Isla by the Auckland District Health Board identified four contributing factors to her death; the emergency obstetric code was not called, Kelly and Yanakopulos were not fully aware of all their birth options or risk factors, there was a possible missed opportunity to increase surveillance of fetal wellbeing and a missed opportunity to diagnose Kelly's ovarian cyst.
However the report suggested the baby was already in a critical condition on arrival in the hospital with a slow heart rate.
An Auckland District Health Board spokesman this week said the board would not comment on individual patient cases.
"Auckland DHB wishes Louise every success with her plans," a statement read.
* If you can help visit the couple's Facebook page or email them on oursurrogatenz@gmail.com
