As a sibling to [name_m]Finnegan[/name_m]? [name_u]Jameson[/name_u] would go by [name_u]Jem[/name_u]. [name_m]Finnegan[/name_m] would primarily be [name_u]Finn[/name_u].
I love both of these names and think they would go really well together. Also, the nickname [name_u]Jem[/name_u] is adorable!
I think they sound great together
They sound pretty perfect together- they have a similar style and length but they don’t rhyme and have distinct nicknames- good choices!