Justin Bieber Twitter Update: Singer Shows Love For 5-Year-Old Baby Sister Jazzy, Wishes Her ‘Happy Birthday’ [PHOTO]

Justin Bieber's Twitter update on Thursday shows the 19-year-old singer celebrating the 5th birthday of his baby sister, "Jazzy" Jazmyn Bieber.

Justin Bieber first mentioned about his sister's birthday when he tweeted at around noon, saying "HAPPY BIRTHDAY @JazmynBieber !!! I love you! #HappyBirthdayJazzy"

Over 80,000 Bieber fans shared and retweeted the pop star's celebratory message, wishing Jazzy a happy day as she turns 5 years old.

Later in the day, three hours after Justin Bieber first posted a "happy birthday" message, the teen pop sensation posted a picture of his little sister on his Instagram account.

The picture shows Justin Bieber's sister lying face down on what it seems to be passenger seats in the back of a car. To caption the photo, Justin Bieber wrote, "The birthday girl is tired."

Jazzy Bieber seems to have had a long day after celebrating her birthday with her brother, Justin. The loving brother shared the news about his sister to his nearly 40 million followers on Twitter.

Even an hour later, at around 3 p.m. EDT, the singer again wrote, "#familytime #HappyBirthdayJAZZY," indicating that he, his sister, and the rest of his family are have a good time together celebrating his young sister's birthday.

Fans from all over the world responded to Jazzy's birthday on Twitter. @milloenchenxoxo wrote as a comment to the baby sister's photo, saying "Happy Birthday Princess."

Other fans thought Jazzy, who was lying face down and sleeping in the passenger seats, was "so cute."

On Wednesday night, Justin Bieber attended the After Earth premiere in New York City. Justin Bieber's best friend, Jaden Smith, stars in the movie.

Justin Bieber also showed his support for the film and his best friend, Jaden on Twitter. He wrote, "Everyone go see #AfterEarth this weekend. @officialjaden we got u. #supportyourfriends"