The Holy Childhood Association is one of the Pontifical Ministries. It has a series of helpful resources for students, parents and teachers.
See also their series of Holy Family Kidz videos:
Here is one example:
From their About Us page:
“The Holy Childhood Association was founded in France in 1843 by Bishop Charles de Forbin Jansen. It’s purpose is to encourage all children to be aware of the needs of children living in mission diocese through the world. Bishop de Forbin Jansen always had a keen interest in the missions. He was a great preacher and traveled throughout France preaching the Gospel. He received letters from missionaries in China requesting his financial help to save starving and abandoned babies there. He did not know how to begin to raise these funds so he met with Pauline Jaricot who had already began her work to raise funds for mission dioceses. She advised him that no one could understand the needs of children better than children. She gave him the idea to start a children’s charity.
In 1843 he called upon the children of France to help save the children of China. He asked them to become Missionary Children, helping to spread the Good News. He asked them to say a Hail Mary every day and give a small coin every month to help feed the Chinese children.
Their motto was “children helping children”. The French children took up this great work and from then on the work of missionary children has spread across the world. Today it is in 110 countries and helps make Jesus known to children all over the world. Under its banner “children helping children”, monies raised through schools are directed towards self-help programmes involving the building of schools, the provision of health and nutrition programmes and medications, school fees, and teaching and learning resources.
Children in communities, orphanages, homes for the disabled, refuges, and those living on the streets are assisted by the generosity of children who wish to make the love of Jesus know everywhere.”