The mother of a young boy with Down syndrome says there is a "happy ending" after her son was excluded from a classmate's birthday party.

Jennifer Kiss-Engele posted on Facebook Saturday morning that the parent organizing the party had reached out to her. 

"The parent read my letter, spoke to their child about Sawyer, and the child created a special birthday invite for Sawyer," wrote Kiss-Engele, of Langley, B.C, referring to her son. 

"Of course he's been beaming ever since and can't stop talking about it."

Kiss-Engele penned a heartbreaking open letter on Thursday after finding out her son was the only child in a class of 23 not invited to a birthday party. She believed it was because Sawyer has Down syndrome.

She implored the other parent not to be scared to talk to her about it, because despite being a "mama bear," she recognized "we all make mistakes."

Kiss-Engele's letter went viral: it was covered by international media and shared nearly 3,000 times.

"I'm really proud that my letter has reached so many people, because it's not just this birthday party and it's not just Sawyer," she wrote. "There are so many kids with special needs [and without, of course] that just don't make the cut."

"I think, as parents, we all need to do a better job of fostering these relationships, myself included."