Tragedy struck the couple in early June when they announced that their youngest child, River Kelly Smith, died following a drowning incident.
RELATED: Granger Smith's son, 3, dies in drowning accident
Over the weekend, Amber shared on Instagram how they decided to donate River's organs.
"I thought, 'How can we bury our sweet baby and not try to help others?'" she wrote on Instagram.
RELATED: 'Good will come out of this': Country singer Granger Smith reflects on grief after 3-year-old son's death
After making the decision and running tests, Amber said the family and hospital staff lined up the hall for the "walk of honor."
"Granger and I held each other and cried. We got the letter that our tiny, red-headed hero gave life to 2 adults. A 49-year-old woman and a 53-year-old man. I cried when we opened it," she wrote.
In June, the couple had shared how they were finding the light within the darkness of losing River.
"We're going to constantly search for ways that good will come out of this," Granger said in a video posted to the family's YouTube channel. "That's my commitment to River's legacy."