maybe develop a bank of normal names in your universe, to find somewhere to jump from. since its just magic!america, is it just magic!johnson and magic!o'neill? or do people get a lil more creative? does this family have a unique name people pick up on, or just something fairly regular?
maybe it could just be something very starkly simple, but with a twist? like coraline. or maybe theyve been witch hunters since before they came to america, in which case, their name could be relevant to witchhunting in their native culture - unless they're native american, in which case you got a whole loada stuff to go from.
You could also reference famous fantasy works and people. Crowley would be a cool one, bc alesteir crowley was a very famous witch... so i guess itd be ironic?