Sylvia Grindelwald's Secret

After Gellert Grindelwald was defeated by Albus Dumbledore, he was imprisoned in Nurmengard, which he had previously created. Later, an Eastern pure-blood wizard admired Grindelwald and voluntarily stayed in Nurmengard. Many years later, Grindelwald's daughter was born, and the Grindelwald family once again welcomed a new head. But this girl seemed to have many secrets, until Dumbledore invited her to become Ravenclaw's deputy headmaster and the teacher of Defense Against the Dark Arts... The male protagonist of this story is uncertain, it may be a subplot, thank you.