I saw, heard, and read many stories of children (mostly protestant) have dreams and visions of God or anything that relates to him. A lot of people believe them but sometimes their visions and/or dreams contradict other people’s testimony of what they saw. Also if you pay close attention of every protestants testimony about them being in heaven and/or hell and see God you will notice some or many contradictions. This makes me wonder if children can be false prophets. Sorry if my writing or everything about this seems messy.
Children’s testimonies are not very reliable. They are really prone to outside influences and may want to tell particularly extravagant stories because they think that is what the adults want from them. An example would be the satanic panic/sex abuse hysteria that used to surround daycare.
Of course children can be false prophets. We don’t go around automatically ordaining anything some child says about God as absolute theology. Children also can be imaginative and manipulated and used.