I'm thinking of using Clíona/Clíodhna for a real BtN baby!
In my accent it's CLEE-uh-na, not quite CLEE-na, but the "uh" is subtle. We'd use Clio, CLEE-oh as a nickname.
Which spelling do you prefer? I kind of prefer Clíodhna, but I think people will struggle with the pronunciation, even if we are using Clio most of the time. Cliona is genus of sponges and I can't really get that out of my mind. I also can't use the fada for either in some official documents here, but that's just the way it is.