The internet is praising 6-year-old Lex Camilleri for the courageous way she stood up for her 9-year-old brother who has autism.

Lex, who lives in southern England, came home upset after school one day, her mother Sophia told BuzzFeed News. Lex said a girl at school had called her brother, Frank, "weird."

Lex tried to explain to her classmate that Frank had autism, but the girl didn't understand the condition. Instead of being angry Lex decided to use this as a perfect teaching moment for her peers, so she wrote a letter on autism awareness.

"My brother has autism and is not weird..." Lex's letter proclaimed.

The following day, she read the letter aloud in class — and it struck a chord.

Lex's mother Sophia decided to share the letter on Facebook in order to campaign for better autism awareness in school.

Lex's letter reads:

"On Monday I felt very sad because a girl in my class said that my brother was weird. 

My brother has autism and is not weird and I would like it if could learn about all disabilities in schools so that everybody understand that some people are different but we should all be treated the same."

While Sophia has since hidden the Facebook post, a cached version of the post from October 24 shows it had been shared 27,000 times and received 21,000 reactions.

The National Autistic Society shared Lex's letter, too.

"We agree wholeheartedly 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," a National Autistic Society spokesperson told BuzzFeed News.

Sophie said Lex has loved the support from people on Facebook, but the mother is upset that her daughter experienced this difficulty at all.

"It makes me really sad that no-one knows about these disabilities, if they were made aware it would change a lot of things. I think it would help kiddies to know about autism and the symptoms that come along with it," Sophie told BuzzFeed News. "I suppose it is confusing for them and it might be a bit of fear, because they don’t know what’s going on with the child."

Lex's attitude toward the ordeal is one of great understanding, and we can only hope other children lead the way like she did. Read her full letter below: