She and Ms Crisp were greeted with a hug by the star and a big smile after winning backstage tickets through The Hits radio station.
Sheeran told them his team had shown them a copy of the video.
Mrs Orr gave him photos of her son and a greenstone paperweight as a symbolic gift.
"Greenstone is found in rivers in the South Island. Andrew grew up in Ruakaka [Northland] by the river and died by a river," said Mrs Orr.
"He [Sheeran] was very gracious about it."
She described the occasion as completing the circle.
After a brief meeting with the pop star, Mrs Orr and Ms Crisp joined family members for the concert.
Orr's girlfriend Caitlin had organised tickets to the show.
-nzherald.co.nz