Thanks for your honest opinions! Yes I did add the name to the baby name finder but the name certainly exists.
I have to say the medical associations of Clelia were lurking in my mind before I asked the question, so I wanted to check it wasn't just me :)
I quite like Cloelia, and the French version, which is Clélie (DH is French so maybe, although it does sound a bit like Kelly). Yes, TotallyUnheardOf, the reason I like it is because it was the name of an ancient Roman heroine. No-one's really heard of her though so there shouldn't be too much pressure to live up to it...