(CNN) Christian Larsen begged his mother, Lindsay, to throw him a ninth birthday party so he could invite all of his friends. Finally, she gave in, sending out invitations -- and waiting.

But only one person RSVP'd.

Christian, who has autism, attends Hillsdale Elementary in Meridian, Idaho. At the picnic marking the end of the school year, Larsen says, she saw firsthand how some of the children interacted with her son: either ignoring Christian or telling him no when he asked them to attend his party. It made her think that there might be something more to the lack of responses.

On May 31, Lindsay posted on Facebook about the lack of responses, and her friend Blythe Ben-David stepped in to make a birthday miracle happen.

Ben-David lives in South Texas, far from the Larsen family. She couldn't be there for the party, so she reached out to Dan Holtry, a family friend and the football coach at Nampa High School in Idaho.

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