Hardy was nearing the end of her one-year term and volunteered to step down early to prevent the need for two elections - one on Monday for a new co-chair and another a month later for her role.
The three candidates who put their hands up for the new co-chair roles were Benjamin Ross, Paris-Lee McLeod and Hardy.
Hardy was elected on the first vote, but Ross and McLeod drew, leading to a second ballot which saw McLeod claim the second post.
Addressing the Youth Committee, McDouall said the role of the Youth Committee was fundamental to ensuring young people's concerns were heard by council.
"At council, we try to do our best. We try to think of the best interests of the youth of the Whanganui District," McDouall said.
"But sometimes the values, the concerns and the voices of the older people drown out the voices of the younger people. That's why the Youth Committee was set up."
McDouall said the committee could prove a stepping stone for those involved, pointing to Whanganui MP Steph Lewis and district councillor Josh Chandulal-McKay who were both involved on or in the formation of the committee.
"This is the first step on the way to you becoming leaders. Use these experiences to build your leadership skills."
Whanganui District Council's Youth Committee members for 2021 are Amber Mars, Benjamin Ross, Carter Baum, Charlotte Hardy (co-chair), Hinerangi Ratana, Keisha Maniapoto, Marie-Claire Mahone, Miriama Joseph, Olivia Archer, Paris-Lee McLeod (co-chair), Rebecca Csore, Siobhan Sarkar, Sophie Archer and Te Paea Maihi Rogers.