Celestia

I know a grown woman with this name (probably about 40 by now): a lovely lady, and a great friend. Though in her own words, she was more of a Rarity than a Princess Celestia (being an excellent seamstress).

Although I like Celeste and Celestine, I think Celestia is the prettiest name with that sound so far. I like that it's associated with stars. It does remind me of the "My Little Pony" princess, but it doesn't bother me.