I would play it safe and stick to reading and raising the little ones on biblical stories.There are so many really exciting and engaging stories that I am sure you and your kids would love.There is noahs ark,daniel in the Lions den,david and goliath,joseph and his coat of many colors,Jonah and the whale etc.
As Christians we are to separate ourselves from the world and things of the world and flee the very appearance of evil.
i believe harry potter stories and the like is the way the devil is using to demonically oppress and indoctrinate our kids.
We are becoming too desensitized to books and movies like harry potter.we really need to ask for more discernment concerning these things so we are not exposing our kids to demonic elements.
cartoons,video games,movies,boardgames and books are not as innocent as they used to be.The devil has a little time left and he will use any avenue he can get while causing us to overlook them.