I think both names are pretty but I perfer
Celia.
Cecilia has a longer sound I think.
At first I thought
Celia was a rather stuck-up name because of a girl I knew, and then I read a book about the Dunne family in Scotland with a daughter named
Celia. Since then I've really liked it!
So I guess I like
Celia better but Ceeilia is pretty too!
I also like
Cecily! :)