Hillary Clinton commemorates Greta Thunberg, Malala Yousafzai on 'International Day of the Girl'
© Greg Nash

Hillary ClintonHillary Diane Rodham ClintonJill Stein: 'I am not a Russian spy' Trump criticizes Clinton for suggesting Jill Stein was Russian asset Graham: I'm seeking to make Trump successful 'but not at all costs' MORE tweeted in support of "International Day of the Girl" on Friday and gave shoutouts to prominent female youth activists whom she labeled "gutsy women," a reference to her new book.

In a tweet, the 2016 Democratic presidential nominee wrote that she was thinking of activists Greta Thunberg and Malala Yousafzai, as well as March For Our Lives members Emma González and Naomi Wadler.

"On this International Day of the Girl, I’m thinking about all the gutsy girls who are changing the world—@GretaThunberg, @Emma4Change, @NaomiWadler, and @Malala, just to name a few—and all those who will. #DayOfTheGirl #GutsyWomen," Clinton tweeted.

Thunberg most recently made headlines as the initial inspiration for marches calling for action to combat climate change that have been held in cities around the world in recent months, as well as her solo sailboat voyage to the U.S.

Yousafzai, who was shot by Taliban gunmen in 2012, is now a student at Oxford University and an advocate for girls' education around the world. She received the Nobel Peace Prize in 2014 for her activism in the face of death threats from Islamist extremists.

González and Wadler, two prominent activists involved in March for Our Lives, joined the movement following a mass shooting in 2018 at Marjory Stoneman Douglas High School in Florida, where González attended school.