Encouraging their followers to donate blood, platelets, or plasma via The Poppy Grace Lifeblood Group, they hope to make the lives of other oncology kids and their parents better.
“We felt honoured to be her mums and we didn’t take a second of that for granted, not a second. She taught us so very much in her short 20 months and we have never experienced a love as all-encompassing,” they said.
Reflecting on their first Mother's Day without their darling baby girl, Carly, and Tresne thanked their fans and followers for the kindness they had shown during this difficult period.
"We just wanted to thank you kind hearts for reaching out with messages of support on Mother's Day."
"Sunday hit us hard. It took a toll, but we're okay, just stacking up our resilience. We miss our baby girl, so much. It feels like a bad dream, it still doesn't feel real."
"We know now that we need to plan to be surrounded by our people on significant days like this."
The couple then went on to add that they spent the day "looking back at treasured time with Poppy Grace."
"We cooked for hours and hours to try to keep our minds and bodies busy."
The emotional update comes after the former reality stars returned from a trip to Thailand in April where they spent time attempting to process their grief and "explore healing a Poppy-sized hole in our hearts."
"Our time in Thailand has helped to give us the tools we need to grow and live through this grief."
Just weeks later on June 2nd, the couple marked another sad milestone as they reflected on what would have been darling Poppy's second birthday.
But whilst they are still in the depths of their grief, the pair used the day to shine a light on a cause close to their heart - blood donation.
"We really wanted to get up and do something that's actionable - and that is to donate blood," they told 7Life.
"It's unbelievable how much cancer kids, and cancer patients in general, need blood. We had no idea prior to this."
"We could go back to our normal lives and not do anything," Tresne said before adding: "But we know how important it was to Poppy and to all her little friends who still need blood."
On August 17th, the couple mark yet another devastating milestone as they reflected upon six months since their darling daughter went to heaven.
"16.8.23. Six months without our sunshine - Poppy Grace. The ache is ever present because we loved you so wholly baby Poppy. You were pure magic ✨," they wrote on their joint Instagram with an accompanying video montage.
"Missing your giggles, your dancing but most of all your unconditional love and wondering if that all-encompassing joy will ever visit us again."
"We will keep pushing, keep getting up in your honour. #riseupforpoppy
"A life should be long...click the link in our bio to donate to Children's Cancer Institute ♥️"
WATCH NOW: Carly and Tresne mark six months without Poppy Grace. Article continues after video.
Find out today if you can donate blood at Lifeblood Australia.
If you'd like to donate to the Children's Cancer Institute click here.