Plus-size Ashley Graham. Photo by Evan Agostini/Invision/AP

American model Ashley Graham has revealed that she shed tears of joy for Danielle Herrington after she was selected to appear on the front cover of Sports Illustrated.

The 30-year-old model has taken to her Instagram account to heap praise on the Compton-born beauty, saying she's proud of Danielle for helping break down boundaries by becoming only the third black woman to appear on the cover of the iconic magazine.

Alongside a photograph of the cover, Ashley wrote: "DANIELLE!!!! Tears of joy for you this morning! Congratulations on breaking even MORE barriers being the 3rd black woman to ever grace the cover of @si_swimsuit! I have so many emotions SOAR BABY GIRL!! @danielle_herrington_ (sic)"

Tyra Banks and singer Beyonce are the only other black stars who have appeared on the front cover of the magazine. 

Read: Danielle Herrington 'beyond speechless' to be Sports Illustrated's cover girl

Meanwhile, Ashley has also been credited with breaking down boundaries within the fashion industry, becoming one of the world's best-known plus-size models.

And the brunette beauty recently revealed that her mother Linda has been a central figure in her career, giving her the confidence she needed to pursue her ambitions.

She shared: "My mom has been my role model since childhood and has played a vital role in developing my confidence. She promoted body positivity in our household before it was a movement."

Ashley and Linda have similarly curvy figures, and Ashley previously admitted to feeling inspired by her mother's self-assured outlook.

Of her influence, she said: "Her feel-good attitude toward her own body has shaped my ability to remain positive and self-assured."