One of my oldest and dearest friends is named
Roisin Emma so the name has a special place in my heart. She spells it without the accents though and I think that it may be simpler that way.
How about:
Roisin Eleanor (I really like this one for some reason)
Roisin FelicityRoisin MirandaRoisin ClaireRoisin HopeRoisin AndromedaRoisin HelenaRoisin GeorgetteRoisin LouisaRoisin LinneaRoisin GraceRoisin BronteRoisin XantheRoisin GraceRoisin Marina
Hope you like some of these ones!