Kurtis was a talented Rotorua rugby player who died in April 2015 after he lost his battle with testicular cancer.
Ewins put her heart and soul into the tribute - from the circular design (to represent an infinity bond) to carving the stand, anchoring it, beading it in, and designing the plaque herself.
The theft has taken her back to her first stages of grief and Ewins has been battling with the shock, saying Kurtis' memory had been violated.
"This is where our loved one is lying and resting and someone has vandalised it; it's caused so much pain," she said.
He said he "couldn't believe someone could stoop so low" and be that "mean-spirited" to take precious taonga placed by the family of a lost loved one.
Rotorua Mayor and chairwoman of the Kauae Cemetery Trust Board, Steve Chadwick said things of this nature were "very distressing and disappointing".
When asked about a possibility of increased security, she said the trust board wanted people to be able to visit their loved ones at any time of the day or night, to make the space open and accessible.
"It's impossible to guarantee protection of taonga that families place on graves but the board will keep working with council staff to consider safety and security."
Rotorua police senior sergeant Karl Konlechner said police wanted to help restore the pounamu and hold those responsible to account.
"It's hard to fathom the lack of empathy or compassion displayed by some offenders," he said.
The theft was reported to the police on July 2 and the pounamu was suspected to have gone missing between June 14 and 21, between visits to the site.
Police have no active lines of enquiry but said they welcomed any information.
Anyone who has seen the pounamu, or has information about the theft can contact Police on 105 quoting file number 190702/0737, or anonymously via Crimestoppers on 0800 555 111.