If you like a name, it shouldn't change if it is number one on the most common list, or if it hasn't even been used for the last one hundred years.
But if you want to have a name that everyone will remember, then read on.
For a long time, no one will be able to use the name Hermione.
Why is that?
It wasn't a common name before it was used, and that would have been the first time many people would have heard it, so it is fixed with that character, and the character will take it to the book's
Say you like the name Genevieve, but it is too common for you.
Another name like it is Guenevere, but again, maybe you don't like it because of the mythology tied to it.
Another one is Gwendolyn.
You may not like it, for a lot of different reasons, so keep changing until you get one that YOU think it right, and don't be afraid to change your character slightly, or change their appearance.
If you like a name, but it doesn't suit your character, than write it down, because, hey, it might be some inspiration for another character.
If you end up changing your character, save your old one, because even if you don't end up using them, you can take small pieces, until the old character has made three new ones, and even then NEVER delete anything, anyone, for at least fifteen years, and even then, make sure you have milked every last, tiny drop, because what you think is insignificant, might later make a star character, or, a writer's true dream, a whole another story, or it might just be a character in a back story, one without a name, but there will always be of use.