Rarely a day goes by when there is not another surprise gift arriving on her doorstep - all because her mother started posting cute pictures of her online.
The Breanna effect snowballed when wealthy, high-profile Emiratis in the United Arab Emirates spotted the cute Korean girl's short videos on the picture sharing website Instagram.
In them, she dances along to Korean pop music, sings along to Miley Cyrus and poses with designer handbags.
When the Emiratis began reposting her videos six months ago, Breanna came to the attention of web surfers across the Middle East, where internet usage is as high as 77 per cent.
Her mother Jocelyn, 27, responded by teaching her phrases in Arabic gleaned off YouTube and signing off each video with the Arabic word "bosaah", meaning kisses, and the fans followed in their droves.
Her wealthy fans in the Middle East even flew her from her home in South Korea to Dubai, where her family has been put up for free in five star hotels since May and chauffeur driven in limos.
Breanna's 1.1m Instagram followers - who have been joined by an average 60,000 new followers per day - dwarf those of Pixie Rose Curtis, the redheaded Australian three-year-old who was dubbed the Princess of Instagram with 90,000 followers, a fraction of the number eager to find out what Breanna does next.
She will equal Diaz within days, who has 1.16m followers, and she is quickly catching up with One Direction's Zayn Malik and Girls creator Lena Dunham, both of whom have 1.2m Instagram fans.
But her popularity is a puzzle to her parents. Mrs Youn told MailOnline: "I don't know why people love Breanna so much. She does not have any special talent that she is good at like dancing and she does not do much on camera. She only does a little drama and smiles and poses.
"But she has something inside her that makes people love her and makes them happy. She is just very sweet.
"Whenever I put her in front of a camera, she is a natural and loves posing."
Breanna, who has a Korean father, 34-year-old Junghyun, and a Filipina mother, speaks four languages, including English, Korean, Tagalog and Arabic.
Her short videos on Instagram show her practising all four languages, dancing along to Shakira and Korean pop music. She also has the occasional meltdown when she wants ice cream or chocolate.
Like America's Honey Boo Boo and much of today's younger generation, Breanna wears her heart on her sleeve and is completely comfortable living her life in public in front of a camera.
She also has 305,000 followers on the short video website Vine and 210,000 fans on a Facebook fan page.
On Vine, she has more than 55m loop counts - the measure Vine uses to record how many times people repeatedly play gifs, or image files.
Her popularity started when Mrs Youn posted pictures of her daughter on her own Facebook page. Strangers begged her to set up a Breanna fan page so Mrs Youn obliged a year ago.
The Vine site was set up shortly after but it was only when she set up OfficialBreannaYoun on Instagram seven months ago - mainly to stop fraudsters from pretending to be her - that Breanna's fame rocketed.
She has attracted hundreds of thousands of fans from Malaysia, Singapore, Indonesia and Saudi Arabia.
"Most of them were posting comments in Arabic," says Mrs Youn.
"There were thousands of them. It was difficult for me to understand so I had to get them translated one by one.
"I have no idea how they found her in the first place but they love her."
Her hundreds of thousands of followers are besotted, with some even telling Mrs Youn: "I love her more than my own children".
One mother posted a message saying her day was not complete until she had seen Breanna online.
Most of her followers in the region are in Saudi Arabia. Breanna has been invited to present on game shows and model everywhere from Bahrain to Indonesia. It was one such invitation that first brought the family to Dubai in May for a fortnight's holiday, which became a permanent stay.
The Youns - who also have a seven-year-old son Braxton - were living in a modest two-bedroomed apartment in Busan, South Korea, and were running a seafood export business when the offer came to fly to Dubai in May.
Since then, they have turned their backs on their Catholic and Mormon upbringings to convert to Islam.
They are still living in Dubai, courtesy of their wealthy benefactors.
Like Pixie's parents Roxy Jacenko and Oliver Curtis, the Youns have been criticised for over-exposing their daughter, who is too young to know any better.
But Mrs Youn said: "As parents, you are happy that people love your children. They fall in line for Breanna's picture at shopping malls.
"Now Breanna knows she is famous. If we go to the mall, she will ask why people are not taking pictures with her. She is used to it.
"In Korea, she got attention and people wanted pictures with her because she is cute. Here, they want to take them because they recognise her from Instagram. It makes us feel really special.
"These famous people love this ordinary little girl and now she is extraordinary."
Mr Youn denied the family was addicted to fame and said he worried about what would happen when Breanna grew up.
He said: "I hope people keep loving her. Sometimes I worry about what will happen in the future when they grow up.
"We cannot stop this now. If Breanna is sick and we do not post a picture or video for three or four days, we are bombarded with thousands of emails from every country asking what happened.
"We are treated like famous actors here. Even if we are in a restaurant and Breanna is hungry, people hug and kiss her and you cannot say no."
Breanna cried when the number of followers reached 600,000, saying: "I am just so happy".
"I love being in Dubai, even though it is very hot."
Her brother added: "I am smart but Breanna is beautiful".
- Daily Mail
