Safyre Terry, from New York, was overjoyed when she received cards in the post after her aunt Liz Dolder posted a request on Facebook.
The card tree that initially had one card on is now overcrowded with Christmas love.
Dolder wrote on the Facebook group dedicated to five-year-old Safyre: "When she said she can't wait to fill up the card tree my response was 'I don't think it's gonna get filled up but I am sure we will get a few more cards'. She believed and all of you are making it happen. Thank you!"
Safyre is the sole survivor of the arson fire that killed her dad David Terry, 32, sister Layah, three, and her brothers Micheal, two, and Donavan, 11 months. In the fire, 75% of Safyre's body was burned.
In the two years since the fire, Safyre has had multiple operations, lost her right hand and her left foot.
She continues to have problem with her mouth due to the scar tissue tightening up and is due for her next operation on 5 January.
On 4 December, Terry received her first Christmas card and was pictured with it on her Christmas card tree.
Dolder wrote on Facebook: "Safyre is thrilled we got our first Christmas card. Thank you Aunt Lonnie. Safyre is excited to fill up the card tree. Sending out lots of Holiday cheer to all."
Many people begun commenting on the photo saying everyone should try to "fill up that tree" for the five-year-old girl.
Others commented saying they would love to get Safyre a Christmas card. Soon, Dolder passed on an address they could send one to.
A friend, Kevin Clark, shared the post and asked his Facebook friends: "I wonder how many of my friends would take the time to write and send Safyre a Merry Christmas card that she can hang on her card tree..."
His post was shared nearly 20,000 times reaching all over the world.
Safyre soon noticed the benefit as she begun receiving Christmas cards through the post very quickly.
"Can someone say glowing? Someone got mail today," Dolder wrote on Facebook on 8 December.
The aunt uploaded four photos of Safyre holding all her post.
An update on 9 December showed Terry decorating her Christmas card tree with all the cards she had received.