I ADORE
Liadan.
Ailis is really pretty too, but not entirely my style. It's made an appearance on my PNL before, though, in previous Irish A-name crazes (
Aoife,
Aine, etc.). Both names together make fabulous twins, IMO.
Ailis Maeve is a little awkward for me. Something about the rhythm and the way the names fit together... eh. I really, REALLY like
Ailis Grainne, though, and it does fit beautifully with
Liadan Isolde (also lovely, though I don't know if I'd be brave enough to use it on this side of the pond).