Marking World Children’s Day at the United Nations in New York, the organizations’ Children’s Fund has named their youngest Goodwill Ambassador who is just 14 years old. Emmy-nominated actress Millie Bobby Brown of “Stranger Things” fame joins an impressive list of UNICEF advocates who speak on behalf of the world’s most vulnerable. As part of the day, UNICEF has a campaign to ‘turn the world blue’ in support of children’s rights globally.

She stars as ‘Eleven’ in the Netflix science fiction horror hit. She received a Daytime Emmy nomination earlier this year for Outstanding Supporting Actress and will now use her platform to advocate for children less fortunate than she is.

“It’s an exciting time because even though I am young this is the point why I’m doing this – so that you hear me as a child; you hear me speak and I want everybody to listen to young people and children. Our voices matter, our voices need to be heard and this is one of the most exciting times of my life because now you will listen to me because I would demand it, I will demand that you listen to all of us,” says 14-year old Millie Bobby Brown.

World Children’s Day is a global day of action “for children by children” to raise awareness and funds for millions of young people who remain unschooled, unprotected or uprooted.

“ Today we are going blue for all those 260 million children and young people who cannot go to school, who have never seen a primary class or a secondary class, also today we are going blue for the 650 (million) girls and women who were married before the age of 18. Also we are going blue for the 5.4 million children younger than 5 years old that are dying every year because of preventable diseases. Today is the day for children by children,” says UNICEF’s Director of Communications Paloma Escudero.

Millie has over 18 million follows on Instagram alone, a powerful platform for someone who is barely a teenager.

“ In becoming a UNICEF Goodwill Ambassador, I share the title with a hero of mine, the late great Audrey Hepburn who once said ‘as you grow older, you will discover that you have two hands, one for helping others and one for helping yourself and that’s exactly what I intend to do.'”

UNICEF is also asking supporters to raise their voices in solidarity by going online and signing a global petition asking world leaders to commit to fulfilling the rights included in the Convention on the Rights of the Child adopted by the General Assembly exactly 29 years ago.