Mr Leckner was full of praise for his wife's commitment.
"Its a big deal for me," he said.
"She's a top girl. She's spent countless nights sitting beside my hospital bed."
However, she needs to lower her BMI before work-up tests will qualify the couple to join the list, as the strict criteria of the scheme ensures only healthy organs are donated.
To lose the required weight, she is participating in the Mums on a Mission 8-Week Winter Challenge, which balances nutrition and exercise to help mums achieve their health and fitness goals.
As she begins her fourth challenge week, her husband has returned home after being in the ICU on dialysis for the past three weeks.
That will make her goal easier, as since the challenge began she has been balancing it with fulltime work, and staying at the hospital "for hours until she got kicked out", her husband said.
Mrs Leckner said the three kilograms she had lost so far didn't seem like much in the big picture, but every bit counted.
"I wouldn't have been able to do it without the support of the other ladies, who know the struggle of losing weight."
Mr Leckner's sister Hayley is also on the paired exchange, as more donor options will increase her husband's chance of receiving a kidney.
The couple believed sharing their story would increase awareness about organ transplants.
They hoped it could inspire more people to consider becoming donors.
Facts about kidneys
•451 people are on the national waiting list for kidney transplants.
•20 people in Hawke's Bay have received kidney transplants in the past three years.
•There are 26 donors for 24 recipients on the paired kidney exchange waiting list
(two recipients have two donors).
•Six transplants from the scheme have been successfully completed.