child_witch_conversion_success_effect

child_witch_conversion_success_effect = {
	scope:child = {
		give_witch_secret_or_trait_effect = yes
		house = {
			house_head = {
				add_to_list = witch_message
			}
		}
		every_parent = {
			limit = {
				is_ruler = yes
				is_witch_trigger = yes
			}
			add_to_list = witch_message
		}
		random_relation = {
			type = guardian
			save_scope_as = guardian
		}
	}
	every_in_list = {
		list = witch_message
		limit = {
			this != scope:child
		}
		save_scope_as = witch_knower
		send_interface_message = {
			type = event_witchcraft_good
			title = witch.1001.message
			left_icon = scope:child
			scope:child = {
				if = {
					limit = { has_trait = witch }
					show_as_tooltip = { add_trait_force_tooltip = witch }
				}
				else_if = {
					limit = { exists = scope:witch_secret }
					scope:witch_secret = { reveal_to = scope:witch_knower }
				}
				add_opinion = {
					target = PREV
					modifier = impressed_opinion
					opinion = 20
				}
			}
			random_secret = {
				type = secret_witch
				limit = {
					NOT = { is_known_by = scope:child }
				}
				reveal_to = scope:child
			}
		}
	}
}

As written in game/common/scripted_effects/00_witch_effects.txt.