Petrider began her work as a girls’ rights activist at 15, when realising that many children’s, especially girls’, rights were violated in her community. She established a girls’ rights club in school which advocated for girls' rights in the community and through social media.
Petrider is passionate about education. She believes girls are undervalued from birth, and regrets that traditions in Tanzania often mean that girls and women are undermined.
She co-founded Youth For Change Tanzania, a partnership of youth striving to end gender-based violence against young girls, especially FGM and child marriage by working in rural communities to educate young girls, traditional and religious leaders and influence policy makers and decision makers on girls’ rights.
Petrider regularly participated in international meetings such as the first African Girls' Summit on Ending Child Marriage, the One Young World Summit and the Girls Not Brides global meeting on ending child marriage. She has addressed the British Parliament on gender-based violence and is also a representative in Tanzania’s youth parliament.
Petrider aims to work as an activist until true gender equality is reached.
“Society can find me modern and look at me badly but as long as I am doing something for my fellow girls I can see past this to a world where gender equality is possible.”