Lex’s letter has been shared more than 28,000 times. The National Autistic Society also shared the post.

A six-year-old girl wrote a heartwarming letter hoping to raise awareness for her autistic brother after a classmate called him “weird.”

Lex Camilleri, who lives in the United Kingdom, was bothered when a classmate said to her, “Your brother is weird.” She told the child her brother has autism, but the child didn’t know what the disability was.

“My brother has autism and is not weird. I would like it if we could learn about all disabilities in schools so that everybody understands that some people are different,” Lex wrote.

Her mother, Sophie Camilleri, posted Lex’s letter on Facebook on Oct. 10, and it has been shared more than 28,000 times. The National Autistic Society also shared the post.

“We agree whole heartedly with Lex’s message, and it’s incredible that, at just 6 years old, she knows that we need better understanding of autism inside and out of our classrooms," Sarah Lambert of the National Autistic Society told the Daily News.

Lambert added that the organization’s "Too Much Information" campaign serves as resource for students to learn more about autism.

“I’m so very proud that Lex has this view and wants to change the way other children view others with disabilities,” her mother wrote on Facebook.

Lex Camilleri’s letter has gone viral after she was mad at a classmate who called her autistic brother “weird.”

Many people on social media also praised Lex for defending her brother.

“You’re a beautiful and caring sister Lex! Great job! It saddens me when people are so judgemental of others and so uncaring,” one Facebook user wrote.

“What an incredible thing for a 6-year-old to have such understanding and consideration of kids less able than herself. You must be so proud!” another user added.

Camilleri did not immediately respond to questions.