This is permissible but not recommended as the rule is that the one memorizing more, leads the prayer. She is too young to pray and too young to demand such a thing. You should encourage her to learn more Quran and make that her incentive.
This is permissible but not recommended as the rule is that the one memorizing more, leads the prayer. She is too young to pray and too young to demand such a thing. You should encourage her to learn more Quran and make that her incentive.