I have a group of four siblings I need to name for my story idea. I have the oldest and youngest already - [name_m]Sean[/name_m] [name_m]Patrick[/name_m] and [name_f]Fiona[/name_f] [name_f]Claire[/name_f] (last name is [name_u]James[/name_u]). The two middle children are identical twin boys. I’d like to keep the Irish theme, as they have Irish heritage, but the names need to be fairly mainstream and match the other two.
All suggestions welcome
[name_m]Ciaran[/name_m], [name_m]Liam[/name_m], [name_u]Finn[/name_u], [name_u]Aidan[/name_u], [name_m]Brendan[/name_m], [name_m]Conor[/name_m], [name_m]Ronan[/name_m], [name_u]Reilly[/name_u], [name_m]Declan[/name_m], [name_u]Dillon[/name_u]/[name_u]Dylan[/name_u] ([name_u]Dillon[/name_u] is the Irish spelling though), [name_m]Eoghan[/name_m]/[name_u]Owen[/name_u] (again, [name_m]Eoghan[/name_m] is the Irish spelling), [name_m]Ruari[/name_m]/[name_u]Rory[/name_u]
All I can think of from the top of my head!
Matchy twinsets:
[name_m]Conor[/name_m] and [name_m]Calum[/name_m]/[name_m]Conor[/name_m] and [name_m]Ciaran[/name_m]/[name_m]Calum[/name_m] and [name_m]Ciaran[/name_m]
[name_m]Ciaran[/name_m] and [name_u]Aidan[/name_u]
[name_u]Rory[/name_u]/[name_m]Ruairi[/name_m] and [name_m]Ronan[/name_m]
[name_m]Brendan[/name_m] and [name_u]Aidan[/name_u]
[name_m]Declan[/name_m] and [name_u]Dylan[/name_u]/[name_u]Dillon[/name_u]
[name_f]Non[/name_f]-matchy:
[name_m]Liam[/name_m] and [name_u]Finn[/name_u]
[name_m]Conor[/name_m] and [name_m]Ronan[/name_m]
[name_u]Aidan[/name_u] and [name_u]Rory[/name_u]/[name_m]Ruairi[/name_m]
Hmm.
[name_m]Sean[/name_m]
[name_m]Conor[/name_m]
[name_m]Jack[/name_m]
[name_m]Mark[/name_m]
[name_m]Eoin[/name_m]
[name_m]Cian[/name_m]
[name_m]Kiernan[/name_m] nn [name_u]Kerry[/name_u]
[name_u]Ryan[/name_u]
[name_m]Luke[/name_m]
[name_u]Dean[/name_u]
[name_m]Kevin[/name_m]
[name_m]Craig[/name_m]
[name_m]Alan[/name_m]
[name_m]Christopher[/name_m]
[name_u]Niall[/name_u] (might not want this because of those pesky 1D fans)
[name_m]Ronan[/name_m]
[name_m]Liam[/name_m]
[name_m]William[/name_m]
[name_m]Jack[/name_m]
[name_m]Samuel[/name_m]
[name_m]Ian[/name_m]
[name_m]Leon[/name_m]
[name_m]Phillip[/name_m]
[name_m]Benjamin[/name_m]
[name_m]Brendan[/name_m]
[name_u]Owen[/name_u]
[name_u]Dillon[/name_u]
[name_m]Callum[/name_m]
[name_m]Jonathan[/name_m]
[name_u]Barry[/name_u]
[name_u]Cameron[/name_u]
[name_u]Neil[/name_u]
[name_m]Eric[/name_m]
[name_u]Reece[/name_u]
[name_u]Sam[/name_u]
[name_m]Colin[/name_m]
That’s all, folks! 
[name_m]Liam[/name_m]
[name_u]Aiden[/name_u]
[name_m]Cormac[/name_m]
[name_m]Declan[/name_m]
[name_u]Sullivan[/name_u]
[name_u]Rory[/name_u]
[name_u]Dillon[/name_u]
[name_u]Shane[/name_u]
[name_u]Finn[/name_u]
[name_m]Eamon[/name_m]
[name_m]Seamus[/name_m]
With the sibset I really like [name_m]Seamus[/name_m] and [name_u]Finn[/name_u].
If you’re writing a story with any historic significance be sure to keep in mind the following Irish naming traditions (obviously not always adhered too but good to know).
First born son named after his father’s father
Second born son named after his mother’s father
Third born son named after his father
Fourth born son named after his father’s oldest brother
Fifth born son named after his father’s 2nd oldest brother
or his mother’s oldest brother
First born daughter named after her mother’s mother
Second born daughter named after her father’s mother
Third born daughter named after her mother
Fourth born daughter named after her mother’s oldest sister
Fifth born daughter named after her mother’s 2nd oldest sister
or her father’s oldest sister