I associate Ceilidh with barn / Irish-y dancing, as I attended a function where we did this!
I pronounce it as KAY-lee but I may be wrong, I'm not Irish.
Caoimhe and
Aislin are lovely, but in an English speaking country (I'm not sure where you're from) I think
Caoimhe may cause a child some issues with misspelling and mispronounciation.