Irwin urges girls to go natural

Bindi Irwin has posted a makeup-free selfie to encourage girls to embrace their natural beauty.

The 15-year-old took to Instagram on Friday to encourage all her "gorgeous girls" to ditch the makeup and photography filters.

To illustrate her point, the Crocodile Hunter's daughter shared a rare, barefaced selfie.

"I don't generally post selfies, but I see so many amazing girls who need to let their true beauty out," she captioned the pic.

"I believe in you. I just wanted to remind you how pretty you are."

"You're loved."

She said there was too much pressure on young girls to live up to a perfect ideal.

"I'm sending you a hug," she said.

"Be true to you."

Irwin's motivational message comes after criticising some of her female peers for dressing too provocatively.

Her comments attracted the ire of former Neighbours starlet Caitlin Stasey.

"In ten years you'll wish you stood beside your shared sex," Stasey tweeted.

However, Stasey stressed she was not attacking Irwin personally, just disagreeing with her views.