Older
"There are lots of other Greek names I like but they generally are hard to read/spell.
Andromeda
Alethia
Thalia
Leto
Lyssa
Phoebe
Rhea
Selene"
"TAR-lee-a" pronunciation gets my vote.
(I love Rhea from your list).
OP,
Celeste's really pretty: always makes me think of celeste the colour (turquoise-blue/ sky-blue), or a celesta, so musical connections, as much as the literal heavenly.
I like Joeybee's character sketches! Interesting how different people interpret a name.
BTW, If you're veering more towards Persephone, yet concerned about people's constant mispronunciation/ misspellings, I doubt (long-term) it'll be any more an issue than Niamh, Aurelia, or even Sara (SAHR-a for some; SAIR-a for others) etc.
Less than a decade ago, Isla was fairly regularly pronounced "ISS-la" by those unfamiliar with it, which certainly hasn't prevented it from since becoming so popular!!
Anglo-Greek friend's daughter (aged 8) is Elysia (Eh-LEE-zee-uh).
To save confusion with Eh-LEE-sha (more common in the US, I think?), she quickly learnt, on first meeting anyone, to throw in "Eh-LEE-zee-uh, like "breezier"...works brilliantly.
Link to familiar rhyming words/ a phrase, and people remember far better 
Best of luck with her entry into the world, anyway... 