Remi, five years old, was heartbroken when only two friends showed up to her birthday party in Abertillery, Wales.
The family had sent out some invitations to around 10 of Remi's pals but they didn't get the response they hoped for after two guests got in touch on the day to say they couldn't make it through illness - but others hadn't RSVPed at all.
Remi's dad, PJ Robins, explained: "It was really very sad that none of them had bothered to respond really. One of the things with the autistic spectrum is that last minute changes are terribly distressing, especially to Remi.
"We'd already told her about the party and that we'd invited her friends so she was expecting her friends to be there.
"At one point she turned around and said 'Mummy, where are all of my friends?' and that was like a knife in the heart."
PJ decided to take action and posted on a local community group on Facebook, asking for people to drop by.
In his post, he said: "Please, if anybody has some free time and has a child around my daughter's age - would you be willing to help us make her party a day to remember.
"We don't expect anything, not cards or gifts, the part is all paid for and there's plenty of food, we just want some children to come help our little girl celebrate."
And the response was incredible - around 14 children and parents turned up and stayed at the party, and a number of random people turned up to wish Remi a 'happy birthday' after seeing the post.
The post was shared more than 1,000 times and PJ said he received around 60 messages from people who'd seen his appeal.
"Remi was a little bit bewildered, if I'm honest," said PJ. "She had two friends there and then suddenly she had all these other people wishing her happy birthday.
"The response was truly overwhelming, and we're still receiving messages from people in connection with the appeal, asking for our address so they can send cards, or drop in and meet Remi.
"A lot of people have also reached out with their own stories of parenting children on the autistic spectrum, offering their support, play dates, and so on."
PJ added: "Thank you to everybody who came down and brought their children."